Print quality study of newsprint Further development of the laboratory offset press at PAPRO Susanna Halonen Emma Magnusson

2002

EXAMENSARBETE Grafisk Teknologi Nr: E2383GT Nr: E2528GT

Susanna Halonen Emma Magnusson Examensarbete, 10p

Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

Acknowledgments We would like to thank all the staff at PAPRO for helping us with our project and making our stay in New Zealand unforgettable. Special thanks to our supervisor Ian Chalmers and our tutor Dr Göran Bryntse (College of Dalarna) for giving us the opportunity to come here and explore New Zealand. Thanks to Alan Dickson and Nicola Dooley who have showed patience and helped us when we have struggled with our work and report. We would also like to express our gratitude to Lynn Collier, for helping us organize all the practical stuff and for being a good friend. Last but not least, a big hug to all the people in the apex building. We have had the best time with you!

DEGREE PROJECT Graphic Arts Technology Programme

Graphic Arts Technology, 120p

Reg number E2383GT, E2528GT

Names

Year-Month-Day

Susanna Halonen Emma Magnusson

Exents

15 ECTS

2002/04/01–2002/06/30 Examiner

Göran Bryntse Company/Department

Supervisor at the Company/Department

PAPRO, Forest Research, New Zealand

Ian Chalmers

Title

Print quality study of newsprint Further development of the laboratory offset press at PAPRO Keywords IGT, Inking unit, Printing unit, Airbrush, Image analysis, Solid area, Halftone dots, Fountain solution, Roughness, Density

Summary A laboratory offset press has been developed over the last five years at PAPRO for testing print quality on newsprint, as at present, there is no good way for the mills to test this issue. In this project a comparison has been made between a laboratory offset press and a commercial press to see if the laboratory offset press can be used as a reliable test method or if a further development is needed. To evaluate the method, similar papers have been printed in both presses and compared using image analysis techniques. All together eighteen samples were tested which is enough to give comparable results. The print quality showed a high variation, the values from the laboratory offset press and the commercial press were not following the same trends. At present time the laboratory offset press need some further development before it can be used as a reliable test method for halftone prints. Even so some conclusions were made. The newsprint that has been used came from Norske Skog Tasman Mill (Kawerau), since the other aim of this project was to do a repeatability study of their three existing paper machines to distinguish possible differences in the production. The paper samples were taken from each paper machine on six different dates to give a representative result. This also gave the opportunity to compare the machines between themselves. Comparison between the machines shows that the wire side gives a better and more even result than the topside on the prints from the laboratory offset press. According to the result from the commercial press the wire side shows a higher degree of variability. Samples from paper machine 2 and 3 were less variable and had the lowest standard deviation of grey level for solid areas. This suggests that newsprints from PM 2 and PM 3 give a more even print quality with a better ink coverage.

Högskolan Dalarna 781 88 Borlänge Röda vägen 3

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EXAMENSARBETE, C-nivå Grafisk Teknik Program

Grafisk Teknologi, 120p

Reg nr E2383GT, E2528GT

Namn

Månad/År

Susanna Halonen Emma Magnusson

Omfattning

10 poäng

03–06 2002 Examinator

Göran Bryntse Företag

Handledare vid företaget/institutionen

PAPRO, Forest Research, Nya Zeeland

Ian Chalmers

Titel

Tryckkvalitetsstudie av tidningspapper Vidareutveckling av laboratorieoffsetpressen på PAPRO Nyckelord IGT, Färgverk, Tryckverk, Airbrush, Bildanalys, Fulltonsyta, Rasterpunkter, Fuktvatten, Ytstruktur, Densitet

Sammanfattning Under de senaste fem åren har en laboratorieoffsetpress utvecklats/tagits fram på PAPRO för att man ska kunna kontrollera tryckkvaliteten på tidningspapper. I dagsläget finns det inte något bra tillvägagångssätt för pappersbruken att testa tryckkvaliteten. I det här projektet har en jämförelse gjorts mellan en laboratorieoffsetpress och en kommersiell press för att se om laboratorieoffsetpressen kan användas som en pålitlig testmetod eller om den behöver vidareutvecklas. För att utvärdera metoden har samma papper tryckts i båda pressarna och jämförts med hjälp av en bildanalysteknik. Allt som allt testades 18 prover, vilket är tillräckligt för att få ett jämförbart resultat. Kvaliteten på trycket visade stor variation. Resultaten från laboratorieoffsetpressen och den kommersiella pressen följde inte samma trend. I dagsläget behöver laboratorieoffsetpressen utvecklas ytteligare innan den kan användas som en pålitlig testmetod. Även om så var fallet så kunde vissa slutsatser dras. Tidningspapperet som använts kommer från Norske Skog Tasman pappersbruk i Kawerau eftersom det andra målet med det här projektet var att göra en repeterbarhetsstudie av deras nuvarande tre pappersmaskiner för att fastställa möjliga olikheter i produktionen. Pappersproverna var tagna från varje maskin vid sex olika tillfällen för att få fram ett representativt resultat. Det gav också möjligheten att jämföra varje maskin individuellt. En jämförelse mellan maskinerna visar att virasidan ger ett bättre och mer jämnt resultat än översidan på trycken från laboratorieoffsetpressen. Resultaten från den kommersiella pressen visar att virasidan har större variationer. Proverna från pappersmaskinerna 2 och 3 har minst variation och också den lägsta standardavvikelsen av gråskalor hos fulltonsytor. Detta medför att tidningspapper från PM 2 och PM 3 ger en mer jämn tryckkvalitet med en bättre färgtäckning.

Högskolan Dalarna 781 88 Borlänge Röda vägen 3

Telefon: Telefax: URL:

023-77 80 00 023-77 80 50 http://www.du.se/

Susanna Halonen Emma Magnusson Examensarbete, 10p

Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

Table of contents 1. Introduction 1.1 1.2 1.3 1.4 1.5 1.6

Company introduction Background Purpose Aim Method Delimitation

2. Laboratory Offset press 2.1 Inking unit

8 8 8 8 9 9 9

10 10

2.1.1 Ink

10

2.1.2 Fountain solution

10

2.2 Printing unit

10

2.2.1 Settings

10

2.2.2 Offset plate

11

2.3 Printing procedure 2.4 Printing problems

3. Development of fountain solution unit 3.1 Airbrush calibration 3.2 Result 3.3 Comments

4. Image analysis 4.1 Equipment 4.2 Image analysis procedure 4.2.1 Sample selection

5. Evaluation of the laboratory offset press 5.1 Result 5.2 Conclusion 5.3 Future work

11 11

12 12 12 12

13 13 13 13

13 14 14 14

6. Newsprint evaluation, Norske Skog Tasman Ltd 15 6.1 Sample preparation 6.2 Printing 6.2.1 Comment

15 16 16

Susanna Halonen Emma Magnusson Examensarbete, 10p

Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

6.3 Image analysis 6.4 Conclusions

16 16

7. Discussion

18

8. References

19

Appendix A

(1)

Inking unit and printing unit

Appendix B

(2)

Plate design

Appendix C

(3)

Printing manual

Appendix D

(4)

Airbrush calibration

Appendix E

(5)

Image analysis manual

Appendix F

(6)

Halftone images Laboratory offset press (IGT) Commercial press (CP)

Appendix G

(7)

Dates

Appendix H Roughness, Density

(8)

Susanna Halonen Emma Magnusson Examensarbete, 10p

Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

Appendix I

(9)

Image analysis data Solid area, IGT Solid area, CP Halftone dots, IGT Halftone dots, CP

Appendix J

(10)

Image analysis graphs CP/IGT (trend line) PM1 CP/IGT (trend line) PM 2 CP/IGT (trend line) PM 3 SD Dot Area IGT/CP (SD of mean SD) SD Dot Area IGT and CP SD Dot Perimeter IGT/CP (SD of mean SD) SD Dot Perimeter IGT and CP Roughness/SD Dot Area (trend line) Roughness/SD Dot Perimeter (trend line) Form Factor GL Sol

Appendix K Glossary

(11)

Susanna Halonen Emma Magnusson Examensarbete, 10p

Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

1. Introduction By printing samples taken on different dates from one paper machine, there is a good opportunity to study how constant the paper machine works considering printability. At present time there is no good way for the mills to test this paper property besides sending the paper to a commercial printing store. This takes time and it is hard to get exceptionally controlled conditions that are desired for this kind of testing. Therefore a faster and more controlled way of testing this property is needed.

1.1 Company introduction PAPRO is a leading Pacific Rim supplier of pulp, paper and packaging technology and operates within Forest Research. Forest Research has integrated science programs across the forestry, wood, fibre, paper and biomaterial sectors. PAPRO consist of three expertise groups covering areas of strategic focus: Paper and Paperboard, Mechanical Fibre Processing and Chemical and Enzymatic Technologies. This project is a part of the Paper and Paperboard group, which works towards improvements in paper and paperboard structure, as related to end-use performance. Expertise within the group relates to papermaking and papermaking chemistry, paper performance, printing and packaging, printability of newsprint, linerboard manufacture and converting, paper recycling, paper physics, performance modeling and surface properties.

1.2 Background For the last five years PAPRO has been developing a laboratory-printing machine for halftone offset to be able to monitor the print quality on newspaper. For the work a rebuild of the IGT F1 Flexo press with an external inking and dampening unit has been used. In previous projects the work has been concentrated on the optimization of the settings to get an acceptable print. For further information see previous students work (see reference list). The last student, A. Lindqvist who worked on this project claims that the prints show enough quality at present time to be used on daily bases for testing the printability on newsprint. However he also says that there are still a few practical changes that can be done to facilitate more reliable results.

1.3 Purpose By request from Norske Skog, each of the three paper machines at Tasman Mill (Kawerau) needs to be compared on a day to day basis to distinguish differences in the production. Furthermore, evaluation of the reliability of the laboratory offset press (IGT) needs to be done since it is desirable for the mills to find a quick and reliable method for testing the printability of their papers.

8

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

1.4 Aim The aim of this project is to identify any deviations considering repeatability of Tasman Mill’s three paper machines by looking at the printability using a relatively new modified laboratory offset press (IGT) and a commercial press (CP). It is also to compare the laboratory printed samples against the commercial prints to evaluate whether the IGT press can be used as a reliable test method or if further development is required.

1.5 Method A study of previous reports and suitable literature is going to be carried out to obtain more information about testing the printability of newsprint. Both the offset press and the image analysis instrument will be tested before the study starts, to establish methods/practices to minimize human error. Where needed, some smaller changes to improve the laboratory offset press will be made. Thereafter paper samples will be collected from the Kawerau Mill and printed both in the laboratory offset press and in a commercial press. The prints will be analyzed, compared and finally evaluated.

1.6 Delimitation Only the given newsprint from Norske Skog will be evaluated considering printability. All the previous settings will be used such as present ink and fountain solution and the amount of these [A. Lindqvist]. The samples will be evaluated by using a CCD camera to acquire the image of the prints. Routines have been prepared at PAPRO to quantify, by image analysis, solid parameters such as print density, print mottle, amount of unprinted areas as well as halftone dot properties such as contrast, size distribution, shape and sharpness.

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

2. Laboratory offset press The laboratory offset press consists of an inking unit, developed at PAPRO and a printing unit that is a modified IGT F1 for flexographic printing.

2.1 Inking unit For the plate inking a special inking unit, designed by I. Chalmers and constructed by R. Hensel, is used. The unit has been modified over the last five years and at present consists of three inking rollers (two made of copper and one made of rubber) and one plate holder. For illustration see Appendix A. The unit has one speed and one pressure setting and both the ink and the fountain solution are applied manually. By first spraying fountain solution onto the rubber roller and then pressing the plate by hand against it, ink is transferred from the inking rollers to the plate. In other words no fountain solution unit to wet the inking plate is used as in a real, commercial press. Here, the dry inking plate receives ink covered and mixed with fountain solution. Due to the correct mixture of ink and fountain solution and the exact time the plate is in contact with the inking unit, the printing areas will stay dry and the non-printing areas become covered with a thin layer of fountain solution. 2.1.1 Ink In earlier work different kinds of ink have been tested [A. Lindqvist, 2002]. The one that gave the best result was CSB015/200 Newspeed black. Therefore, this ink has also been used in this project. 2.1.2 Fountain solution The fountain solution consists of 2% DIOL Green fountain concentrate and 98% distilled water.

2.2 Printing unit The standard anilox roll is replaced with an offset inking plate and the flexo printing plate is replaced by an offset blanket. The inking plate cylinder has half the circumference of the blanket cylinder, which means that the test area is printed twice on each strip. An impression roller is used to provide backpressure at the printing nip but has also the function to feed the sample; for figure see Appendix A. 2.2.1 Settings The settings that can be altered are printing speed, printing force and inking force. The printing speed is the speed that the substrate travels between the impression roller and blanket cylinder. The inking force is the force of the printing plate onto the blanket cylinder and the printing force is the force of the impression roller onto the blanket cylinder. To get the right degree of penetration of ink into the paper previous work 10

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

has shown that both the printing force and inking force should be set to 450 N and the printing speed to 0.3 m/s [M. Myohanen, 1999]. 2.2.2 Offset plate The negative plate that is used is baked to resist damages and increase plate life. The dimensions of the plate are 50mm x 200mm and consists of a 58mm x 40mm solid pattern and six 17mm x 17mm halftone dot patterns. These squares have a screen ruling of 70 lpi, 100 lpi and 133 lpi and the theoretical dot coverage of 10% or 30%. For illustration see Appendix B.

2.3 Printing procedure Due to the presence of fumes from cleaning solvents, the inking unit and the printing unit are placed and used in a fume cupboard. Before printing, the room temperature should be warmed up to 23° C and be kept at that temperature during the whole printing. The printing unit needs to be warmed up for approximately one hour before any printing is carried out. The correct amount of ink should be measured with the IGT pipette and distributed on the inking unit. It takes about five minutes for the ink to be completely distributed over the inking roller. Fountain solution should be sprayed on the ink layer using the airbrush. Three one second sprays should be applied approximately every three seconds. After the last spray, wait 15 seconds ”even out time” (the waiting time after the last delivery of fountain solution into the ink before the emulsified ink is transferred to the offset roll [A. Lindqvist 2002]) to let the fountain solution emulsify and to even out the ink surface. Press the plate holder firmly against the ink roller for four seconds to ink; place one hand on each side of the plate holder to ensure an even pressure at application. Immediately after inking, place the printing plate on the printing unit and print. Leave the printing strip to dry at room temperature (23°C) for at least 24 hours before any measurements are done. For printing manual see Appendix C.

2.4 Printing problems During the test runs and also the study, various printing problems have occurred. The main problem was delivered amount of fountain solution; the effect of too much fountain solution being poor inking. The outcome of this problem is a low print density, which results in poor contrast and brightness. Conversely, too little fountain solution results in unprinted areas becoming covered with ink. The main source of human error was to get an even pressure of the plate on the inking unit and to get the same pressure every time. An uneven pressure gives an uneven density, which is undesirable. Another problem was the delivery of ink from the IGT pipette to the inking unit. If the pipette was held upright for a long time air bubbles form in the ink and cause problems, reducing the amount of ink coming out from the pipette. An easy way to solve this was to hold the pipette upside down and shake it before every new ink supply. 11

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

3. Development of fountain solution unit Several test runs with the laboratory offset press showed that the present way of adding fountain solution is not suitable. To use an airbrush that does not deliver the same volume of fountain solution each time and with such big variations, can not be accepted. It is desirable that 0.33 ml (3 x 0.11ml) fountain solution is added before every new print, but at present this changes from 0.25 ml to 0.40 ml depending on (among other things) how full the bottle is and how many turns the control knob is turned. The control knob determines, along with the pressure, the amount of fountain solution that comes out from the nozzle.

3.1 Airbrush calibration To obtain the delivered volume of fountain solution to the inking unit a weight test was done. The airbrush container was filled to the top with fountain solution and the pressure was set to 30 psi. Earlier work shows that 30 psi gives the best results [A. Lindqvist, 2002]. The fountain solution was sprayed into a flask, three sprays for each measure, and weighed. One milliliter (1 ml) fountain solution approximates to one gram (1 g) so the required weight should be 0.33 g. Different turns of the control knob were tested. After finding the right number of turns the fountain solution bottle was filled up to different levels and tested again. The reason for this was that it showed an extremely variable result when the bottle was filled and when it was almost empty. For data and results see Appendix D.

3.2 Result Best results were shown at a pressure of 30 psi, when the control knob was turned 2 turns and the bottle contained 20–60% fountain solution. Still, the airbrush is not constant and the amount of fountain solution that is delivered on each spray changes from time to time. Therefore, a check of the amount delivered should be carried out after each printing round (nine prints).

3.3 Comments Further development of adding fountain solutions is necessary since the present way still does not gives a satisfactory result. Even though the method has been improved, each ”spray” is still too variable to be reliable. The best way is to do further development on this present airbrush method and in some way make the sprays equal in volume. According to A. Lindqvist, one suggestion is to do further automation of the ”black box”, which controls the airbrush, that includes a program with three one second sprays. This is a good idea but to begin with the sprays have to deliver the same amount (or close to) every time.

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

4. Image analysis Image analysis is a processing and data reduction system, which produces a numerical or logical result from an image. A microscope with CCD video camera captures the image, which is then analyzed using a computer with a frame grabber and image analysis software.

4.1 Equipment The PAPRO image analysis system is composed of • Leica MZ12 stereomicroscope • Ring light, a fluorescent light with a design that allows the uniform, vertical illumination of the sample. • JVC TK-C1381 CCD color video camera with resolution 750 x 480 pixels. • Coreco Oculus F/64 frame grabber • Computer • Optimate 6.2, image analysis software.

4.2 Image analysis procedure The image analysis system requires 90 minutes to reach operational stability after the camera and light have been switched on. To ensure the repeatability of the measurements it is necessary to calibrate the apparatus before it is used. Furthermore, even when the camera is warm, the average gray level will continue to decrease with time. So, if the camera is used throughout the day, the calibration should be checked every four hours [C. Antoine, 1997]. A calibration of the black and white values is necessary to get a reliable result. To use the equipment and how to calibrate, see Appendix E. 4.2.1 Sample selection A densitometer should be used to make a distinction of the best looking prints that are going to be used for the image analysis. Each strip should be measured at least three times over a solid area to get a mean value of the density. A low standard deviation of these values is required since a print with equal values all over the area is better to use than a print with big differences through the area. A good result is an even solid area.

5. Evaluation of the laboratory offset press The press in the commercial printing store was not optimized for newsprint since they normally print brochures, leaflets etc. and uses a sheet fed press (newsprint is printed in web offset presses). Further more, different ink/plates/blankets etc. were used and were also factors of the comparison difficulties. The values from the laboratory press and the commercial press were not following the same trends, which made the comparison even more complicated. Even so some conclusions were made. 13

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

5.1 Result The print quality overall shows high variation. Even though the method of adding fountain solution has been further improved it still does not give a satisfactory result. This results in a different print density every time. The images are captured in the grey level range 0–255. Compared to the commercial press, the laboratory offset press produced print which had, as expected, a higher grey level value since the print density was lower. However, the print density was still too high (the density should be close to 0.85 but is at this moment >1). A good result will be when the print density remains constant for every print. The dots on the laboratory prints are not as good as the commercial prints; they are more uneven and spiky and have higher dot perimeter value. Figures are shown to give an appreciation of what we are dealing with, Appendix F. Overall, the commercial press shows less variable results. As mentioned before, this is probably due to lack of optimization of the conditions. For data and graphs see Appendix I–J and for glossary see Appendix K. The halftone dot quality gives a huge insight into the ink/paper relationship. The quality of the dot parameters gives a good indication of the paper’s printability. However the printing process itself plays a major role and because a sheet fed process was used some differences would be expected compared with a web fed one.

5.2 Conclusion At present time the laboratory offset press does not fulfill all the demands for being a reliable test method for newsprint. Further development is still required.

5.3 Future work During this project several problems were encountered. To eliminate these problems or at least improve the method, further development is needed. First of all the way of adding fountain solution has to be improved, since the present way does not give a constant result (see chapter 3). Further to this, the laboratory where the offset press is located needs better air conditioning control, as the temperature varies and the relative humidity is not controlled at all. A redesign of the halftone areas on the plate would facilitate the image analyze work. At present, the plate contains of six 17mm x17mm halftone dot patterns of different lpi and percent dot coverage but only one is used for the image analysis (the 100 lpi with a dot coverage of 30%). If this area was bigger, more measurements could be performed to give a more representative value. Another option is to have several different kinds of plates depending on what kind of work that has to be done. It is also desirable that the plate for the laboratory offset press and the plate for the commercial press contain the same features. The plate for the commercial press unfortunately does not have an area with 100 lpi with dot coverage of 30%, so the image analysis must be done in 100 lpi with 32% 14

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

dot coverage. Even though this is not considered a big difference it would be better if the conditions were exactly the same. There are still some significant improvements according to A. Lindqvist that need to be done. One thing would be to reduce the amount of ink applied, since the measured dot coverage remains to be relative high compared with the theoretical dot coverage. Further to this, more studies of the actual shear rate range in the normal printing process are needed. In theory the shear rates for this laboratory scale-printing unit are two or even three times higher than the range used in rheometer test. The following practical improvements are recommended: 1) Attach a stopwatch on the wall close to the printing unit for the ”even out time” of inking. This will not be necessary when the automatic unit for pressing the plate against the inking is in use. 2) Construct a stand for the IGT pipette for holding it upside down during the printing to prevent air bubbles forming in the ink. It should be mentioned that during this project an automatic unit for pressing the plate against the inking unit has been constructed and may now be tested. This will greatly reduce one of the sources of human error.

6. Newsprint evaluation, Norske Skog Tasman Ltd As mentioned earlier, one of the purposes of this study was to assess the repeatability of the print quality of the three existing paper machines at Kawerau Mill on a day to day basis. For this work the laboratory offset press and the commercial press was used and the prints were compared using analysis apparatus.

6.1 Sample preparation Samples of 45 g/m2 commercial newsprint were collected from the Norske Skog Tasman Kawerau Mill. The samples were taken on different dates from their three paper machines when they showed a ”typical” variation, which means the variation that might occur on a normal day. In total 18 samples were taken; 3 machines on 6 different dates. Physically collected samples should be kept in lightproof bags or in reels during time before using. To establish which side was the topside, the Parker Print Surf roughness test was performed on each sheet. Most of the samples showed a clear difference between top and wire side. Those that didn’t were in addition visually inspected in bright light to find wire marks, before a decision was made. For results see Appendix H. To distinguish the machine direction from the cross direction a tensile strength test was done on Alwetron TH1, the cross direction has a lower tensile strength. For printing in the laboratory offset press the samples were cut in 15

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

strips, 55mm x 650mm, along the machine direction. Nine strips from both top side and wire side were cut. For the commercial press, five sheets from both sides were marked, shuffled and finally cut into A4 sheets in the printing store. Unfortunately, the samples from the mill were to small to run in machine direction in the commercial press and were therefore run in the cross machine direction.

6.2 Printing The laboratory offset press that was used was the rebuilt IGT F1 press at PAPRO. For further procedure information and settings for the laboratory offset press see chapter 4. The commercial offset printing took place at Advocate Press. A Ryobi 524 HX (A3), four-colored sheet fed offset press was used. The ink that was used was Toyo, Hyecoo and the fountain solution was Vans Aqueous AC. The special prepared test plate was used on the last unit of the press. It must be mentioned that the commercial printing store was given wrong ink by mistake from one of the members of PAPRO. The results are therefore based on the prints from the laboratory offset press. 6.2.1 Comment In the laboratory printing process the test area was printed twice on the sample strip. The first print consistently gave higher dot coverage compared to the second, and also showed a clearer print. Therefore, the conclusions and the image analysis are based on the results from the first printed area.

6.3 Image analysis The sample selections for the image analysis were performed both with a Macbeth RD 918 densitometer and visual assessment to distinguish the best looking prints. All prints were measured three times on the solid area to get a mean value of the print density. The five best prints were then used for the image analysis. For mean density values see Appendix H. A different plate design was used for the commercial printing than for the IGT press. The commercial plate did not contain an area with dot coverage of 30% and 100 lpi, which was determined in earlier work to be the test area. Therefore the measurements were done in the most similar area that contains the same lines per inch but with a higher dot coverage of 32%. Measurements of interest are for example grey level, dot coverage and dot perimeter. For glossary see Appendix K. When analyzing the images, both solid and halftone areas were measured ten times on each print. Unprinted areas were measured five times per print, since this is considered enough to get a reliable result.

6.4 Conclusions The standard deviation of dot area and standard deviation of dot perimeter are considered to be the most important and best parameters when evaluating newsprint grades. Comparisons between the machines at the 16

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Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

Tasman Mill show that the wire side gives a better and more even result than the topside. On the topside, PM 2 gives the more consistent results. Sample number 5 has the lowest value, which indicates the best print quality. Considering the wire side, PM 1 gave a slightly better result. According to the result from the commercial press, the results from the wire side show a higher degree of variability. Samples from all three paper machines gave similar values for the form factor, around 1.40 on most of the samples printed with the IGT. There is no significant difference between the topside and wire side. There was little difference between the standard deviation of grey level for the samples printed with the IGT. The top side and wire side results were the same. Sample 2 and 5 from PM 1 showed the highest standard deviation of grey level for solid areas. Samples from PM 2 and PM 3 were less variable and had the lowest standard deviation of grey level for solid areas. This suggests that the newsprints from PM 2 and PM 3 give a more even print quality with a better ink coverage. The roughness does not effect the printabilty. For all data and graphs see Appendix I–J.

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Susanna Halonen Emma Magnusson Examensarbete, 10p

Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

7. Discussion All the conclusions are based on the knowledge that similar ink has been used in both offset presses. It showed later that the wrong ink, with totally different rheological properties, was given to the commercial printing store. Unfortunately this was something that we could not affect since we did not have the responsibility to supply the commercial printing store with ink and paper. Anyway, this is the reason that no correlation can be found. Earlier work shows that the laboratory offset press can be a reliable test method for newsprint and it is probably these results that are correct. The commercial printing store did not have all the facilities necessary to allow a “scientific” approach to the evaluation of printability. For example, the printing room did not have constant temperature or humidity control. This resulted in runability problems and that the printed papers became cockled and difficult to analyze. Controlled air conditions are essential because of the behavior of paper and ink is closely related to the temperature and relative humidity of the atmosphere. The air conditioning system must heat and humidify the surrounding area during the cold months and cool and dehumidify the surrounding area during the warm months. There must also be provision for good ventilation and filtration, with uniform circulation throughout the air-conditioned room. Suggested conditions for the printing hall are 22–23°C and 35–50% RH. Furthermore, in the commercial environment, a densitometer was not used for checking the print density, only a visual estimation was made, which is not good enough to give accurate results. For comparison work of this kind the printing conditions must be controlled and, in particular, be the same at any given time. The principal problem with the laboratory offset press was to maintain the correct amount of fountain solution on the inking unit. The application volume could not be controlled effectively during and between the printing sessions. The laboratory printing conditions were variable, and the temperature changed between 18 and 23° C very quickly. This, as mentioned before, has an effect on the paper and the relationship between ink and fountain solution. To secure consistent results, the inking unit and printing unit should be stored in a special room where better control of the temperature and humidity could be achieved. Furthermore, the printing on the laboratory offset press took place over several days. An even print quality is best achieved by printing in constant conditions, preferably without breaks. At the moment the inking unit needs to be cleaned after nine prints before a new printing session can take place; this may mean a different result for the same paper from an earlier print. This was not a factor for the commercial printing as it was done during one day and one print run.

18

Susanna Halonen Emma Magnusson Examensarbete, 10p

Högskolan Dalarna Grafisk Teknologi Print quality study of newsprint

8. References Literature Glassman A. (1985) Printing Fundamentals. TAPPI, Technology Park, Atlanta, USA. ISBN 0-89852-045-2 Oittinen P. and Saarelma H. (1998) Printing - Papermaking Science and Technology. Fapet Oy, Helsinki, Finland. ISBN: 952-5216-13-6 Bureau W. (1982) What the printer should know about paper. Graphic Arts Technical Foundation. Pittsburgh, U.S. ISBN: 0-88362-013-8

Reports Antoine C. (1997) Development of an image analysis system for print quality evaluation. PAPRO Forest Research, Rotorua, New Zealand. Report No: C724 Burhén, T. and von Sivers, M. (2000) The Development of a laboratory halftone offset printing method for newsprint. PAPRO Forest Research, Rotorua, New Zealand. Swedish degree project No: E1959GT Lindqvist A. (2002) Development of a laboratory halftone dot printing method. PAPRO Forest Research, Rotorua, New Zealand. PAPRO Science Report. Myohanen M. (1999) Development of offset printing on a modified IGT F1 laboratory press. PAPRO Forest Research, Rotorua, New Zealand. Report No: C798

Internet http://www.forestresearch.co.nz, 12/05/02

Personal communication Chalmers, I. Group leader, PAPRO, Forest Research, Rotorua, New Zealand [email protected] Dickson, A. Scientist, PAPRO, Forest Research, Rotorua, New Zealand [email protected] Dooley, N. Scientist, PAPRO, Forest Research, Rotorua, New Zealand [email protected] Howard, M. Project leader, Norske Skog Research, Kawerau, New Zealand +64 7 323 3047 (reception) Williams, S. Research Technician PAPRO, Forest Research, Rotorua, New Zealand [email protected]

19

Appendix A Inking unit and printing unit

Inking unit

The plateholder On/off switch

Inking rollers

Printing unit Blanket Cylinder

Plate Cylinder

Impression Cylinder

Appendix B Plate design, IGT

Plate design, IGT

Screen Ruling, lpi 70

100 133

PAPRO

This Column 30% Dot coverage

200 mm

This Column 10% Dot coverage

Appendix C Printing manual 1(2)

Updated printing manual 2002-05-23 A detailed description of the procedure for the inking and printing process on the modified IGT FI laboratory press.

Preparations • Temperature in the room should be approximately 23° C. • Turn on the printing machine and warm up, approximately for 1/2–1 hour. • Remove the cling film from the copper inking rollers and clean the whole inking unit using tissues and blanket wash. • Attach the printing plate on the plate holder with strong two-sided tape. In the printing unit, attach a strip of blanket to the flexo plate cylinder in the same way. • Adjust both the printing force and inking force to 450 N and set the speed to 0.3 m/s. • Prepare the fountain solution and fill up the airbrush container to approximately 60%. Turn the control knob 2 1/2 turns. Place the stand against the inking unit according to the black mark, on the right hand side of the stand, and make sure that the airbrush nozzle points straight to the inking unit. • Turn on the air supply (clockwise) and set the air pressure to 30 psi. • Plug in the programmed timer. • Attach one sample strip (55mm x 460mm) onto the sample carrier with a piece of tape at each end. The strip should be under slight tension. • Fill the IGT ink pipette with ink. • Put a few drops of singer oil on the axles of the inking rollers as the inking unit is turned on. • Place the rubber distribution roller in position on top of the copper inking rollers when the inking unit is moving.

Inking • Measure the correct amounts of ink, in this case 0.35 ml, with the IGT pipette and distribute it on the inking unit. The ink should be applied as evenly as possible and distributed over the full width of the left side of the rubber roller (only the left half of the inking unit should be used, the right side may cause an uneven printing). After five minutes, the ink should be completely distributed. • Spray the fountain solution on to the ink layer using the airbrush that is connected to the programmed timer. Three 1-second sprays should be applied approximately every three seconds. • Wait 15 seconds (this is the ”even out time”) after the last spray to allow the fountain solution to emulsify and to evenly cover the ink surface. • Place the plate cylinder on the IGT disk holder above the inking unit. To ink the plate, set it down against the top roller of the inking unit for 4 seconds. • After inking, immediately place the printing plate on the printing unit.

Appendix C Printing manual 2 (2)

Printing • Place the sample carrier onto the short carrier guide so that the start (left hand end) of the sample is directly underneath the printing cylin der. • To print, press both the operation buttons on the left and right ends of the machine. When the text ”Apply ink” appears in the dialogue screen release one the operating buttons and then depress again. When the cylinders are stationary, both operating buttons are released. • Remove the printing strip from the sample carrier and leave to dry at room temperature, 23° C, for approximately 24 hours. • Remove the printing plate from the printer and place back on to the disk holder, without cleaning, in the inking unit. Use a piece of cotton textile fabric dampened with blanket wash to remove most of the ink from the blanket cylinder. The surface of the blanket does not have to be totally spotless between prints, but must be cleaned thoroughly at the end of the printing run. Make sure the blanket is dry before the next printing. • Add 0.04 ml ink to the inking unit before the next print.

Finishing • The printing plate has to be cleaned after nine prints. Use a paper tissue dampened with blanket wash to clean the surface of the plate. The plate has to be cleaned very gently to avoid scratching the surface. • Clean the whole inking unit after nine prints, blanket wash can be used for this purpose. • Clean the airbrush container after the tests and unplug the programmed timer. • Close off the air pressure and turn off the main air supply. • After cleaning, cover the surface of the copper rollers with singer oil and cling film.

Airbrush calibration Different amount of F.S in spray bottle

2 1/4 turn

2 1/2 turn

60

50

50

40

40

Volume (ml)

Volume (ml)

60

30 psi, 2 1/4 turns

30 20 10

30 psi, 2 1/2 turns

30 20 10

0 0

20

40

60

80

0

100

0

Bottle volume (%)

60

80

100

2 1/2 turns (ml)

Volume:

SD

Max:

Min:

Volume

SD

Max:

Min:

0-100%

31,11

9,30

59,03

0,01

36,15

7,98

46,48

10,87

20-60%

28,04

2,51

33,07

23,72

34,84

3,14

41,12

30,10

SD

Max:

Min:

2

27,49

3,78

33,63

14,06

2 1/4

30,17

2,44

35,51

23,65

2 1/2

34,42

4,27

47,35

26,95

Appendix D

20 measurments at 30 psi (ml) Volume:

Airbrush calibration

Differences between numbers of turns

Turns:

40

Bottle volume (%)

2 1/4 turns (ml) Bottle volume:

20

Appendix E Image analysis manual

Image analysis manual A detailed description of the procedure for carrying out image analysis on solid and halftone printed areas using a Leica MZ 12 stereomicroscope, a CCD video camera and the software Optimate 6.2.

Preparations • Switch on the camera and ring light and warm up, for approximately 1 1/2 hour before making any measurements. The ring light should be turned to 1 and 1/2 light bulb. • Turn on the computer and open Optimate 6.2.

Calibration When the equipment has reached an acceptable temperature the luminance must be calibrated. This procedure is the same for both ”halftone dots” and ”solid areas”, with the exception of the macro used. To start the calibration do as follows: • Start to run the macro by clicking on Macro – Run on the top menu. Chose which one that should be used, halftone dots or solid areas, from: Print/AnalyseHalfToneDotsVer2_0.mac (magnification set to 6.3) or Print/AnalyseSolidsVer2_0.mac (magnification set to 2.5)

• To calibrate, put the black standard under the camera. Focus (easiest way is to focus on the border around the white calibration area) and set the black density value to 230 and the white to 20, by changing the con trast and brightness. A variation of ± 0.5 is acceptable for both parame ters. To decrease the density, increases the contrast and decrease the brightness. The values changes slightly from time to time but the follo wing are recommended values to start with: Halftone Dots: Solid Areas:

BRIGHTNESS

CONTRAST

116 110

118 106

• When the density value is set push the ”0” button and follow the instructions to start measure.

Measuring The image analysis procedure is explained in the software by instruction windows that pop up every time setting or parameter is changed. To get a reliable value, 10–15 measurements should be performed on the solid area and the halftone area and at least 5 measurements on the unprinted area (when measuring solid area). Try to spread out the measurements but still do them in the same area as the density was measured.

Appendix F Halftone images 1 (2)

Halftone dots, IGT 30% Dot Coverage, 100 lpi

PM 1 15/4/02 Top side

PM 1 4/4/02 Wire side

PM 2 22/3/02 Top side

PM 2 21/4/02 Wire side

PM 3 22/3/02 Top side

PM 3 14/3/02 Wire side

Appendix F Halftone images 2 (2)

Halftone dots, CP 32% Dot Coverage, 100 lpi

PM 1 15/4/02 Top side

PM 1 4/4/02 Wire side

PM 2 22/3/02 Top side

PM 2 21/4/02 Wire side

PM 3 22/3/02 Top side

PM 3 14/3/02 Wire side

Appendix G Dates

Sample Number - Date Date Sample No:

PM 1

PM 2

PM 3

1:

3/4/02

12/3/02

9/3/02

2:

4/4/02

17/3/02

13/3/02

3:

11/4/02

20/3/02

14/3/02

4:

12/4/02

21/3/02

20/3/02

5:

15/4/02

22/3/02

21/3/02

6:

16/4/02

25/3/02

22/3/02

Appendix H Roughness, Density

Roughness Top side PM 1

Wire side

PM 2

PM 3

PM 1

PM 2

PM 3

Sample No:

Mean

SD

Mean

SD

Mean

SD

Mean

SD

Mean

SD

Mean

SD

1

3,65

0,32

3,64

0,26

3,93

0,17

3,66

0,27

3,67

0,21

4,33

0,09

2

3,72

0,15

3,87

0,23

4,04

0,23

3,86

0,21

3,89

0,22

4,22

0,24

3

4,19

0,14

3,78

0,20

3,84

0,26

4,19

0,07

3,83

0,19

4,03

0,16

4

3,72

0,17

3,57

0,17

4,04

0,20

4,06

0,24

3,61

0,20

4,08

0,14

5

3,74

0,25

3,86

0,18

3,77

0,30

4,01

0,27

3,96

0,35

4,02

0,27

6

3,76

0,33

3,73

0,22

3,86

0,14

3,90

0,28

3,73

0,21

4,05

0,17

Density IGT Top side PM 1

Wire side PM 3

PM 2

PM 1

PM 2

PM 3

Sample No:

Mean

SD

Mean

SD

Mean

SD

Mean

SD

Mean

SD

Mean

SD

1

1,08

0,007

1,10

0,004

1,04

0,009

1,07

0,005

1,08

0,008

1,07

0,016

2

1,02

0,009

1,06

0,022

1,08

0,008

1,04

0,022

1,08

0,013

1,09

0,005

3

1,08

0,005

1,06

0,005

1,08

0,012

1,03

0,016

1,07

0,012

1,08

0,013

4

1,09

0,005

1,10

0,008

1,04

0,011

1,09

0,011

1,10

0,008

1,06

0,014

5

1,09

0,004

1,05

0,011

1,05

0,004

1,01

0,013

1,08

0,008

1,07

0,004

6

1,09

0,007

1,06

0,013

1,07

0,011

1,08

0,004

1,08

0,008

1,08

0,010

Density CP Top side PM 1

Wire side

PM 2

PM 3

PM 1

PM 2

PM 3

Sample No:

Mean

SD

Mean

SD

Mean

SD

Mean

SD

Mean

SD

Mean

SD

1

1,20

0,026

1,18

0,030

1,21

0,023

1,21

0,024

1,19

0,028

1,17

0,031

2

1,19

0,024

1,18

0,026

1,20

0,025

1,19

0,013

1,19

0,024

1,17

0,027

3

1,19

0,029

1,21

0,038

1,21

0,021

1,20

0,025

1,19

0,027

1,18

0,028

4

1,19

0,025

1,19

0,032

1,18

0,022

1,21

0,019

1,19

0,033

1,19

0,024

5

1,17

0,022

1,19

0,049

1,18

0,019

1,21

0,022

1,20

0,022

1,19

0,025

6

1,19

0,019

1,19

0,033

1,21

0,029

1,20

0,027

1,20

0,021

1,18

0,019

Appendix I Image analysis data 1 (4)

Solid area, IGT PM 1 Topside 02-04-03 02-04-04 02-04-11 02-04-12 02-04-15 02-04-16 Wireside 02-04-03 02-04-04 02-04-11 02-04-12 02-04-05 02-04-16

PM 2 Topside 02-03-12 02-03-17 02-03-20 02-03-21 02-03-22 02-03-25 Wireside 02-03-12 02-03-17 02-03-20 02-03-21 02-03-22 02-03-25

PM 3 Topside 02-03-09 02-03-13 02-03-14 02-03-20 02-03-21 02-03-22 Wireside 02-03-09 02-03-13 02-03-14 02-03-20 02-03-21 02-03-22

GLsol

SD GLsol

GLsol2

SD GLsol2

Contrast

Optical Density

Optical Density2

Print Density

Spotarea

Total SpotArea

60,98 66,32 61,50 60,27 59,18 57,63

12,16 13,84 12,07 11,49 11,85 12,08

62,00 67,37 62,47 61,26 60,22 58,53

9,58 10,70 9,32 8,77 9,30 9,40

158,47 152,98 157,53 158,73 160,74 161,16

2,22 2,09 2,20 2,23 2,27 2,31

2,19 2,06 2,18 2,21 2,24 2,28

2,02 1,89 2,00 2,03 2,07 2,11

0,00054 0,00065 0,00055 0,00062 0,00055 0,00058

4,95 5,07 5,09 5,31 5,05 5,29

69,42 64,96 65,07 60,06 65,53 58,16

13,99 15,04 14,63 12,77 16,21 12,99

70,42 65,82 65,75 60,93 65,97 59,04

11,13 11,67 11,40 10,11 12,06 10,36

166,03 154,67 153,86 158,63 152,21 160,11

2,03 2,12 2,11 2,24 2,10 2,29

2,00 2,10 2,10 2,22 2,10 2,27

1,94 1,92 1,92 2,04 1,89 2,09

0,00062 0,00073 0,00071 0,00066 0,00093 0,00063

5,02 5,28 5,58 5,31 6,27 5,17

GLsol

SD GLsol

GLsol2

SD GLsol2

Contras

Optical Density

Optical Density2

Print Density

Spotarea

Total SpotArea

57,52 61,69 63,56 57,14 61,75 59,85

11,53 13,00 13,71 11,55 12,89 11,46

58,58 62,61 64,44 58,13 62,69 60,95

8,82 9,66 10,25 9,10 9,43 8,95

159,95 156,60 154,25 160,47 154,34 157,90

2,31 2,20 2,15 2,32 2,20 2,25

2,28 2,18 2,13 2,29 2,17 2,22

2,10 2,00 1,94 2,11 1,98 2,04

0,00058 0,00074 0,00091 0,00055 0,00068 0,00054

5,09 5,77 6,19 4,96 5,29 4,92

60,84 62,41 63,26 59,21 60,08 58,93

12,99 13,12 12,61 13,15 12,39 13,01

61,61 63,30 64,21 60,11 61,06 59,81

9,93 9,96 9,34 10,26 9,45 10,18

156,44 156,05 154,83 158,29 157,22 159,22

2,22 2,18 2,16 2,26 2,24 2,27

2,20 2,16 2,13 2,24 2,22 2,25

2,01 1,98 1,95 2,05 2,03 2,07

0,00069 0,00078 0,00071 0,00085 0,00067 0,00066

5,61 5,77 5,65 6,11 5,52 5,26

GLsol

SD GLsol

GLsol2

SD GLsol2

Contras

Optical Density

Optical Density2

Print Density

Spotarea

Total SpotArea

59,65 59,03 59,98 60,86 61,93 58,00

12,92 12,51 12,71 12,73 13,85 12,45

60,44 59,89 60,79 61,75 62,68 58,90

10,06 9,73 9,84 9,35 9,92 9,64

157,67 158,16 158,18 155,91 155,24 159,30

2,25 2,27 2,24 2,22 2,19 2,30

2,23 2,25 2,22 2,20 2,18 2,27

2,04 2,06 2,04 2,00 1,98 2,08

0,00067 0,00068 0,00072 0,00072 0,00068 0,00065

5,46 5,50 5,31 5,77 5,04 5,38

65,57 58,45 61,24 65,58 59,95 60,90

13,54 11,67 12,88 13,52 12,33 12,61

66,46 59,32 62,00 66,40 60,80 61,78

10,06 8,93 9,67 10,17 9,53 8,96

152,39 158,97 156,81 152,01 157,60 156,16

2,10 2,28 2,21 2,10 2,24 2,22

2,08 2,26 2,19 2,08 2,22 2,20

1,90 2,07 2,00 1,89 2,04 2,01

0,00071 0,00061 0,00067 0,00078 0,00066 0,00072

5,55 5,19 5,52 5,90 5,38 5,47

Appendix I Image analysis data 2 (4)

Solid area, CP

PM 1 Topside 02-04-03 02-04-04 02-04-11 02-04-12 02-04-15 02-04-16 Wireside 02-04-03 02-04-04 02-04-11 02-04-12 02-04-05 02-04-16

PM 2 Topside 02-03-12 02-03-17 02-03-20 02-03-21 02-03-22 02-03-25 Wireside 02-03-12 02-03-17 02-03-20 02-03-21 02-03-22 02-03-25

PM 3 Topside 02-03-09 02-03-13 02-03-14 02-03-20 02-03-21 02-03-22 Wireside 02-03-09 02-03-13 02-03-14 02-03-20 02-03-21 02-03-22

GLsol

SD GLsol

GLsol2

SD GLsol2

Contras

Optical Density

Optical Density2

Print Density

Spotarea

Total SpotArea

48,99 50,74 50,54 49,01 49,07 51,31

13,92 14,45 14,16 14,51 14,38 14,71

49,59 51,31 51,67 50,17 50,11 52,40

12,32 12,73 11,99 12,49 12,36 12,76

169,10 168,30 168,77 170,03 169,70 168,26

2,57 2,51 2,51 2,56 2,57 2,49

2,55 2,49 2,48 2,53 2,53 2,46

2,36 2,31 2,32 2,36 2,37 2,30

0,00043 0,00044 0,00043 0,00044 0,00046 0,00044

3,64 3,72 3,64 3,73 3,88 3,57

47,54 40,34 40,40 38,46 40,16 41,61

15,41 13,80 13,05 13,48 13,17 12,85

47,84 40,87 41,09 38,90 40,74 42,53

13,63 11,95 11,19 11,59 11,29 11,10

171,50 142,72 142,83 143,52 142,50 141,16

2,61 2,15 2,15 2,22 2,16 2,11

2,60 2,13 2,13 2,20 2,14 2,08

2,41 1,99 1,99 2,05 1,99 1,95

0,00052 0,00042 0,00042 0,00043 0,00043 0,00039

3,98 3,48 3,38 3,57 3,54 3,16

GLsol

SD GLsol

GLsol2

SD GLsol2

Contras

Optical Density

Optical Density2

Print Density

Spotarea

Total SpotArea

52,80 51,78 48,00 50,22 52,06 54,25

14,97 14,58 15,47 14,49 15,07 14,39

54,13 53,08 48,98 51,48 53,39 55,24

12,86 12,43 13,55 12,47 12,86 12,74

166,01 165,20 168,72 166,75 167,55 164,80

2,45 2,48 2,60 2,53 2,47 2,40

2,41 2,44 2,56 2,48 2,43 2,37

2,25 2,26 2,38 2,31 2,27 2,20

0,00046 0,00047 0,00049 0,00045 0,00045 0,00046

3,50 3,73 3,85 3,65 3,44 3,58

51,22 50,33 51,65 48,43 47,95 52,85

16,35 15,63 14,04 15,80 15,81 16,07

52,18 51,29 53,06 49,40 48,89 53,40

14,21 13,36 11,82 13,76 13,84 14,59

167,48 166,62 164,57 168,72 168,92 166,52

2,49 2,52 2,48 2,58 2,60 2,44

2,46 2,49 2,44 2,55 2,57 2,42

2,29 2,31 2,26 2,37 2,39 2,25

0,00049 0,00051 0,00046 0,00051 0,00049 0,00049

3,87 4,15 3,73 4,06 3,90 3,64

GLsol

SD GLsol

GLsol2

SD GLsol2

Contras

Optical Density

Optical Density2

Print Density

Spotarea

Total SpotArea

56,78 55,06 55,36 57,87 57,59 56,58

18,11 18,25 18,40 16,31 16,71 18,49

57,20 55,38 55,63 59,23 58,82 57,64

16,30 16,43 16,78 14,05 14,46 16,33

157,86 159,28 160,80 157,53 158,07 158,74

2,33 2,38 2,37 2,30 2,31 2,33

2,32 2,37 2,36 2,26 2,27 2,30

2,10 2,15 2,15 2,08 2,08 2,11

0,00045 0,00044 0,00044 0,00041 0,00040 0,00042

3,33 3,33 3,25 3,29 3,17 3,20

59,55 58,39 57,89 55,98 56,02 60,14

16,50 16,08 16,71 18,32 18,22 16,72

60,33 58,98 59,27 56,92 57,06 61,62

14,56 14,32 14,39 16,31 16,09 14,31

156,20 156,13 158,21 159,84 159,82 155,06

2,25 2,29 2,30 2,35 2,35 2,24

2,23 2,27 2,26 2,33 2,32 2,20

2,03 2,05 2,08 2,13 2,13 2,01

0,00044 0,00043 0,00041 0,00041 0,00044 0,00041

3,52 3,39 3,17 3,17 3,32 3,14

12,25 12,57 13,10 12,28 12,20 11,82

12,94 12,56 12,16 12,63 11,87 11,61

77,44 77,04 77,26 79,26 77,85 80,82

75,94 76,22 77,77 75,80 79,00 83,00

52,64 21,98 31,34 37,48 24,92 35,62

24,37 35,01 69,23 42,21 35,44 23,67

mGL

CA_ Sharp

Contrast

PM 3

Topside 02-03-09 02-03-13 02-03-14 02-03-20 02-03-21 02-03-22 Wireside 02-03-09 02-03-13 02-03-14 02-03-20 02-03-21 02-03-22

54,43 97,80 45,26 29,31 44,47 53,95

12,25 12,76 11,60 12,79 11,78 13,12

81,59 81,14 83,07 75,96 82,86 77,33

52,61 72,55 39,98 23,68 76,34 64,44

12,03 12,74 12,38 12,39 11,45 12,62

83,04 79,85 79,22 77,91 84,46 79,94

mGL

CA_ Sharp

Contrast

PM 2

Topside 02-03-12 02-03-17 02-03-20 02-03-21 02-03-22 02-03-25 Wireside 02-03-12 02-03-17 02-03-20 02-03-21 02-03-22 02-03-25

44,12 101,56 115,77 68,56 36,15 76,75

12,46 12,79 13,05 12,86 11,98 13,11

80,09 79,26 79,60 79,65 81,70 79,44

42,24 78,63 42,98 78,15 125,92 41,51

mGL

11,26 12,37 11,60 12,18 13,84 12,61

CA_ Sharp

83,43 80,53 82,99 82,73 78,49 83,97

Contrast

Topside 02-04-03 02-04-04 02-04-11 02-04-12 02-04-15 02-04-16 Wireside 02-04-03 02-04-04 02-04-11 02-04-12 02-04-15 02-04-16

PM 1

1,25 0,45 0,65 0,76 0,49 0,81

0,44 0,74 1,70 0,99 0,77 0,44

sdGL

1,30 2,16 1,11 0,64 0,97 1,22

1,27 1,89 0,85 0,49 1,78 1,25

sdGL

0,90 2,48 3,00 1,60 0,81 1,65

0,94 1,79 0,98 1,80 4,24 0,92

sdGL

-0,10 -0,03 -0,05 -0,05 -0,04 -0,05

-0,03 -0,05 -0,18 -0,07 -0,05 -0,03

skGL

-0,14 -0,62 -0,09 -0,04 -0,11 -0,10

-0,14 -0,31 -0,06 -0,03 -0,27 -0,16

skGL

-0,12 -0,64 -0,93 -0,28 -0,05 -0,31

-0,07 -0,36 -0,07 -0,35 -1,07 -0,10

skGL

-0,56 -0,23 -0,33 -0,38 -0,26 -0,35

-0,25 -0,36 -0,40 -0,44 -0,36 -0,24

kGL

-0,41 0,30 -0,43 -0,30 -0,38 -0,54

-0,43 -0,25 -0,39 -0,23 -0,31 -0,49

kGL

-0,29 0,40 1,11 -0,23 -0,34 -0,18

-0,38 -0,11 -0,46 -0,22 1,70 -0,30

kGL

52,30 21,82 31,18 37,25 24,81 35,39

24,26 34,83 69,21 41,94 35,22 23,49

modeGL

54,38 98,24 45,03 29,14 44,31 53,72

52,38 72,67 39,78 23,52 76,28 64,25

modeGL

43,97 101,99 116,76 68,52 35,86 76,72

41,98 78,69 42,73 78,31 127,39 41,39

modeGL

50,69 21,32 30,37 36,38 24,21 34,35

23,73 33,89 65,60 40,67 34,29 23,06

minGL

52,15 92,81 43,47 28,36 42,90 52,03

50,53 68,75 38,64 22,95 73,02 62,41

minGL

42,59 95,52 107,13 65,46 34,92 73,45

40,83 74,77 41,49 74,65 111,67 39,97

minGL

53,96 22,44 32,00 38,28 25,42 36,50

24,81 35,78 71,19 43,29 36,27 24,12

maxGL

55,77 99,81 46,43 30,00 45,47 55,21

53,96 74,49 40,89 24,19 78,18 65,68

maxGL

132,23 132,29 118,86 70,20 132,54 78,44

132,36 132,16 44,01 79,90 132,30 42,47

maxGL

44,48 44,68 47,76 42,16 45,92 42,94

45,22 42,20 43,68 41,00 44,74 43,82

Dot Coverage

40,90 41,42 41,62 44,58 41,88 42,88

41,42 40,74 42,28 43,92 39,74 43,48

Dot Coverage

41,40 41,42 40,06 41,82 42,02 41,86

44,84 38,76 45,66 38,98 36,24 46,28

Dot Coverage

495,40 494,20 491,80 504,60 501,00 498,40

498,00 502,20 500,80 503,00 501,80 500,40

Dot Number

496,40 501,20 502,40 494,00 493,60 492,20

492,60 506,20 504,40 502,20 500,20 488,60

Dot Number

503,60 499,60 509,80 500,00 500,20 505,40

498,00 502,40 502,00 505,40 511,20 514,74

Dot Number

30862,43 31032,37 33757,04 29344,13 31772,07 30101,88

31467,65 29309,74 30392,19 28535,51 30943,55 30712,49

M_Dot Area

28893,89 28614,21 28907,00 30719,31 29708,25 30226,28

29345,13 28311,15 29161,49 30470,88 28104,23 30788,62

M_Dot Area

28887,73 28747,91 27608,97 28968,55 29337,93 29069,19

31111,25 27067,99 31629,23 27114,47 24911,75 32215,01

M_Dot Area

Halftone dots, IGT

2673,59 3049,21 3859,41 2318,07 2256,22 2601,90

2591,12 2551,72 2901,18 2688,43 2524,17 2082,46

SD_Dot

2181,45 2334,57 2058,71 3078,24 2134,63 2784,36

2407,05 2784,09 2582,78 2493,01 1877,63 2450,94

SD_Dot

2758,12 3844,56 2217,59 2698,36 2401,05 2525,45

3019,86 2262,21 3006,25 2064,42 3190,60 3105,67

SD_Dot

904,66 874,68 916,22 857,13 873,28 844,51

882,79 857,52 885,91 843,38 873,11 851,19

M_Dot Peri

842,90 838,83 826,16 881,34 834,44 877,56

830,96 844,06 850,61 863,12 793,27 856,46

M_Dot Peri

828,04 858,33 832,67 846,14 827,09 836,44

861,09 800,76 872,32 798,36 836,44 905,04

M_Dot Peri

84,63 84,26 103,98 73,27 66,05 73,57

80,26 78,52 86,63 84,29 78,25 65,53

SD_Dot

70,45 68,85 63,24 85,11 67,05 79,85

70,84 79,56 76,08 66,75 60,72 68,11

SD_Dot

74,64 107,68 72,65 77,12 70,35 72,65

82,56 70,13 85,86 68,42 93,29 84,06

SD_Dot

1,46 1,41 1,41 1,42 1,38 1,38

1,41 1,42 1,44 1,42 1,41 1,37

FormF

1,40 1,41 1,37 1,43 1,37 1,43

1,37 1,42 1,41 1,40 1,34 1,38

FormF

1,38 1,43 1,42 1,41 1,37 1,39

1,38 1,38 1,39 1,37 1,51 1,46

FormF

18,70 18,14 18,57 18,68 18,59 18,85

18,53 18,70 19,31 18,67 18,47 18,67

Dot Mottle

19,42 19,62 19,13 18,33 19,26 19,03

19,15 19,04 18,84 18,42 19,41 19,17

Dot Mottle

19,23 19,50 19,91 19,17 18,85 18,94

18,95 19,41 19,13 19,35 20,08 19,56

Dot Mottle

17,84 18,10 22,33 15,48 19,25 16,66

18,78 15,43 17,11 14,23 17,96 17,60

DotGain

14,79 14,35 14,80 17,61 16,05 16,85

15,48 13,88 15,20 17,23 13,56 17,72

DotGain

14,78 14,56 12,80 14,90 15,47 15,06

18,22 11,96 19,03 12,03 8,61 18,74

DotGain

Appendix I

Image analysis data 3 (4)

10,63 10,38 10,59 10,45 10,18 10,54

10,35 10,27 10,54 10,63 10,69 10,02

87,59 87,70 86,99 84,76 85,95 86,33

86,44 85,37 85,86 85,59 86,17 86,31

55,50 53,34 48,57 48,80 52,24 43,54

58,90 61,39 71,26 43,82 43,18 48,55

mGL

CA_ Sharp

Contrast

PM 3

Topside 02-03-09 02-03-13 02-03-14 02-03-20 02-03-21 02-03-22 Wireside 02-03-09 02-03-13 02-03-14 02-03-20 02-03-21 02-03-22

25,98 93,41 71,63 115,30 93,08 120,34

10,88 10,85 10,35 10,69 10,95 11,36

86,77 92,96 93,46 94,19 94,33 93,59

21,40 96,21 69,72 107,33 102,09 123,09

10,25 10,43 10,95 10,46 10,26 10,53

86,72 93,36 93,48 94,99 93,76 94,58

mGL

CA_ Sharp

Contrast

PM 2

Topside 02-03-12 02-03-17 02-03-20 02-03-21 02-03-22 02-03-25 Wireside 02-03-12 02-03-17 02-03-20 02-03-21 02-03-22 02-03-25

19,79 17,73 24,65 28,47 30,83 24,20

12,61 11,04 11,92 11,79 11,24 10,58

85,05 86,86 84,55 85,38 85,90 87,30

15,61 31,18 20,02 23,08 27,77 18,87

mGL

11,60 9,43 11,53 10,50 11,29 10,93

CA_ Sharp

84,64 86,47 84,36 88,09 85,03 86,95

Contrast

Topside 02-04-03 02-04-04 02-04-11 02-04-12 02-04-15 02-04-16 Wireside 02-04-03 02-04-04 02-04-11 02-04-12 02-04-15 02-04-16

PM 1

1,93 1,84 1,72 1,68 1,96 1,57

2,07 2,19 2,86 1,46 1,44 1,81

sdGL

0,81 2,69 2,11 3,00 2,55 3,60

0,65 2,69 2,06 2,70 2,51 3,34

sdGL

0,58 0,50 0,73 0,84 0,95 0,69

0,51 0,92 0,63 0,69 0,75 0,57

sdGL

-0,07 -0,07 -0,06 -0,06 -0,07 -0,05

-0,08 -0,09 -0,12 -0,05 -0,05 -0,06

skGL

-0,02 -0,52 -0,31 -0,81 -0,56 -0,94

-0,01 -0,56 -0,28 -0,67 -0,56 -0,80

skGL

-0,02 -0,02 -0,03 -0,03 -0,04 -0,02

-0,01 -0,07 -0,02 -0,02 -0,02 -0,02

skGL

-0,67 -0,63 -0,55 -0,61 -0,64 -0,52

-0,69 -0,72 -0,84 -0,53 -0,52 -0,58

kGL

-0,33 0,12 -0,14 0,86 0,38 1,53

-0,24 0,24 -0,26 0,40 0,26 0,92

kGL

-0,22 -0,20 -0,29 -0,33 -0,36 -0,25

-0,19 -0,27 -0,24 -0,26 -0,31 -0,21

kGL

54,54 52,29 47,67 47,87 51,24 42,71

57,86 60,46 70,12 42,89 42,33 47,46

modeGL

25,45 93,64 71,24 116,07 93,28 121,10

21,03 96,52 69,35 107,96 102,44 123,75

modeGL

19,49 17,41 24,28 28,05 30,32 23,83

15,35 30,87 19,58 22,66 27,27 18,47

modeGL

52,75 50,84 46,21 46,54 49,52 41,41

55,97 58,22 66,94 41,88 41,25 46,06

minGL

25,03 87,46 67,51 107,06 86,96 109,05

20,58 90,10 65,93 100,88 96,30 113,57

minGL

19,03 17,09 23,70 27,33 29,50 23,29

14,97 29,79 19,22 22,16 26,82 18,15

minGL

57,48 55,15 50,30 50,52 54,25 45,14

61,05 63,62 74,26 45,27 44,63 50,39

maxGL

26,78 95,95 73,72 118,24 95,60 124,25

22,04 98,73 71,75 109,75 104,51 126,78

maxGL

20,37 18,24 25,36 29,32 31,81 24,90

16,12 32,05 20,62 23,78 28,49 19,45

maxGL

40,18 39,96 39,94 39,10 39,24 39,90

39,52 39,20 39,00 39,92 40,12 39,20

Dot Coverage

38,88 39,02 40,38 38,84 39,42 39,42

39,78 40,12 39,36 39,66 39,68 40,22

Dot Coverage

40,57 38,96 40,02 39,48 40,00 39,46

41,10 40,42 41,36 40,16 41,42 40,06

Dot Coverage

544,60 546,80 547,00 553,00 550,80 551,60

547,20 547,80 547,80 550,20 542,40 543,60

Dot Number

547,00 549,00 547,20 552,40 549,33 546,20

544,67 541,80 549,80 546,40 552,50 546,00

Dot Number

533,67 553,60 548,00 550,40 554,80 552,20

548,25 501,98 547,80 552,20 546,20 550,00

Dot Number

25951,92 25830,65 25776,39 25296,96 25324,11 25778,77

25532,99 25413,34 25252,86 25801,28 25912,37 25346,95

M_Dot Area

25265,06 25205,78 26108,70 25145,64 25464,41 25431,50

25859,71 26077,67 25401,27 25690,36 25689,81 26018,63

M_Dot Area

26469,73 24986,30 25587,50 25222,54 25655,27 25354,66

26362,03 25922,24 26538,86 25829,06 26625,10 25669,14

M_Dot Area

Halftone dots, CP

1438,44 1430,78 1566,71 1394,97 1608,47 1459,54

1483,78 1621,24 1556,21 1489,82 1434,01 1435,10

SD_Dot

1507,59 1688,81 1350,80 1420,27 1518,55 1662,36

1388,23 1383,06 1521,92 1432,47 1479,52 1345,73

SD_Dot

2285,15 1487,51 1728,77 1642,12 1649,53 1519,14

1561,17 1503,39 1527,13 1446,64 1474,30 1556,00

SD_Dot

782,32 781,54 783,78 777,31 785,09 764,16

779,64 776,72 789,96 781,92 772,63 782,02

M_Dot Peri

757,10 759,60 748,26 747,45 762,24 776,95

749,42 758,87 755,73 746,20 750,75 758,86

M_Dot Peri

774,41 753,77 795,46 784,21 778,27 750,18

758,37 760,52 781,85 749,85 787,59 760,56

M_Dot Peri

55,90 55,98 57,69 60,36 64,24 55,68

59,02 62,23 64,86 56,02 55,87 60,50

SD_Dot

55,17 56,56 47,01 50,99 54,45 59,24

49,48 48,88 52,73 48,88 47,77 49,75

SD_Dot

111,53 53,70 63,58 61,99 60,69 55,24

50,81 52,81 52,52 48,14 56,03 51,13

SD_Dot

1,37 1,37 1,38 1,38 1,39 1,34

1,38 1,38 1,41 1,38 1,36 1,39

FormF

1,35 1,35 1,31 1,33 1,35 1,38

1,32 1,33 1,34 1,32 1,33 1,33

FormF

1,41 1,35 1,40 1,40 1,37 1,33

1,32 1,33 1,36 1,32 1,36 1,34

FormF

21,20 21,08 21,12 21,74 21,98 20,70

22,10 22,03 22,19 21,05 20,82 21,86

Dot Mottle

20,68 22,10 21,13 22,49 22,51 23,15

19,77 21,37 22,24 22,01 21,11 22,03

Dot Mottle

20,61 20,59 20,64 20,98 20,83 20,37

19,45 20,21 19,76 20,40 20,12 20,18

Dot Mottle

8,23 8,04 7,95 7,21 7,25 7,96

7,58 7,39 7,14 7,99 8,17 7,29

DotGain

7,16 7,07 8,47 6,98 7,47 7,42

8,08 8,42 7,37 7,82 7,82 8,33

DotGain

9,03 6,73 7,66 7,09 7,77 7,30

8,86 8,18 9,13 8,03 9,27 7,79

DotGain

Appendix I

Image analysis data 4 (4)

Appendix J CP/IGT (trend line) PM 1

Results from CP plotted against those obtained from the IGT; PM 1 SD Dot Area Top

SD Dot Area Wire

y = 0,0561x + 1355,8

y = -0,1093x + 2018,1

2

R2 = 0,0465

R = 0,3539 1600 1550 CP 1500 1450 1400 1800

2200

2600

3000

3400

2400 2200 2000 CP 1800 1600 1400 1200 2000

2500

3000

y = 0,1887x + 36,678 R2 = 0,4813

SD Dot Perimeter Top

SD Dot Perimeter Wire

58 56 54 CP 52 50 48 46 65

70

75

R2 = 0,2456

80

85

90

95

60

100

70

80

90

R2 = 0,5181

120

1,42 1,40

1,36 CP 1,34

CP

1,32

1,38 1,36 1,34

1,35

1,40

1,45

1,50

1,32 1,34

1,55

1,36

1,38

1,40

IGT

52

46 CP 42

49

38

48 60

65

70

55

60

65

70

75

IGT

y = 0,0111x + 14,219 2

R = 0,0011

15,0 CP 14,0

13,5

13,0

13,0 13

14

R2 = 0,0016

16,0

CP 14,0

IGT

y = -0,029x + 14,041

SD GL Sol Wire

14,5

12

1,48

34

IGT

15,0

1,46

R2 = 0,3774

50

51

SD GL Sol Top

1,44

y = 0,4761x + 11,009

GL Sol Wire

CP 50

55

1,42 IGT

y = 0,0508x + 46,848 R2 = 0,0209

GL Sol Top

11

110

y = -0,0446x + 1,4385 R2 = 0,0014

Form Factor Wire

y = 0,2439x + 0,9928

1,38

1,3 1,30

100

IGT

IGT

Form Factor Top

4000

y = -0,241x + 80,448

80 75 70 CP 65 60 55 50 60

3500

IGT

IGT

15

12,0 12

14

16 IGT

18

Appendix J CP/IGT (trend line) PM 2

Results from CP plotted against those obtained from the IGT; PM 2 SD Dot Area Top

SD Dot Area Wire

y = -0,0665x + 1586,9

y = 0,0428x + 1420,7 R2 = 0,0177

2

R = 0,093

1550

1800 1700 1600 CP 1500 1400 1300 1200 2000

1500 CP

1450 1400 1350 1300 1800

2000

2200

2400

2600

2800

3000

5

2200

2400

2600

IGT

SD Dot Perimeter Top

3200

3400

R2 = 0,0807

2

R = 0,2992

65 60

52 CP 50

CP

48

55 50 45

46 58

62

66

70

74

78

40

82

60

64

68

72

IGT

76

80

84

88

IGT

y = 0,1034x + 1,1822

Form Factor Top

Form Factor Wire

2

R = 0,1123

y = 0,4767x + 0,6762 R2 = 0,2471

1,35

1,40

1,34

1,36

CP 1,33

CP 1,32

1,32 1,31 1,30

1,32

1,34

1,36

1,38

1,40

1,42

1,28 1,36

1,44

1,38

1,40

y = -0,3399x + 71,998

GL Sol Top

1,42

1,44

1,46

IGT

IGT

GL Sol Wire

2

R = 0,1598

y = 0,2191x + 37,081 R2 = 0,0403

56

56

54

54 CP

3000

y = 0,1477x + 43,205

SD Dot Perimeter Wire

y = 0,1363x + 39,992

54

2800 IGT

52

CP

50 48

52 50 48

46 56

58

60

62

64

66

IGT

46 58

16,0

61

62

63

64

y = 1,0805x + 1,7017 R2 = 0,1688

SD GL Sol Wire 17

15,5

16

CP 15,0

CP 15

14,5

14

14,0 11,0

60

IGT

y = 0,2978x + 11,146 R2 = 0,4759

SD GL Sol Top

59

12,0

13,0 IGT

14,0

13 12,0

12,5

13,0 IGT

13,5

Appendix J CP/IGT (trend line) PM 3

Results from CP plotted against those obtained from the IGT; PM 3 SD Dot Area Top

SD Dot Area Wire

y = 0,1371x + 1152,9

y = 0,034x + 1388,1

2

R = 0,2554

1650

R2 = 0,0572

1700 1600

1550 CP

CP 1500 1450

1400

1350 1800

2000

2200

2400

2600

2800

3000

3200

1300 2000

2200

2400

2600

2800

IGT

3000

SD Dot Perimeter Top

SD Dot Perimeter Wire

y = 0,037x + 56,833

3400

3600

3800

4000

y = -0,1299x + 68,823

2

R = 0,0059

66

R2 = 0,259

66

64

64

62

62

CP 60

CP 60

58

58

56

56

54 60

70

80

90

54

100

60

70

80

IGT

Form Factor Top

Form Factor Wire

y = 0,1949x + 1,1057 R = 0,0782

1,42

90

100

110

IGT

y = 0,0922x + 1,2437

2

R2 = 0,0262

1,42 1,40

1,40 CP

CP 1,38

1,36

1,38 1,36 1,34

1,34 1,36

1,38

1,40

1,42

1,44

1,32 1,36

1,46

1,38

1,40

IGT

GL Sol Top

1,42

1,46

1,48

y = -0,029x + 59,793

GL Sol Wire

y = 0,4726x + 28,225 R = 0,3241

59

1,44

IGT

R2 = 0,0025

2

62

58 CP

3200

IGT

60

57

CP 58

56

56

55 54 57,5

54

58,5

59,5

60,5

61,5

56

62,5

58

60

SD GL Sol Top

62

SD GL Sol Wire

y = -1,0601x + 31,349

68

R2 = 0,1063

R = 0,3299 20

18,5

19

18,0

4,5

CP 17,5

17,0

18 17 16

16,5 16,0 12,0

66

y = 0,426x + 11,655

2

19,0

64

IGT

IGT

12,5

13,0 IGT

13,5

14,0

15 11,0

11,5

12,0

12,5 IGT

13,0

13,5

14,0

Appendix J SD Dot Area IGT/CP (SD of mean SD)

Mean Standard Deviation of Dot Area PM 1 PM 1 - Top side

PM 1 - Wire side

4000

4000

3500

3500

3000

3000

2500

IGT CP

2000

2500

1500

1500

1000

1000

500

500

0

IGT CP

2000

0 3/4/02

4/4/02 11/4/02 12/4/02 15/4/02 16/4/02

3/4/02

4/4/02 11/4/02 12/4/02 15/4/02 16/4/02

PM 2 PM 2 - Top side

PM 2 - Wire side

4000

4000

3500

3500

3000

3000

2500

IGT CP

2500

2000

2000

1500

1500

1000

1000

500

500

0

IGT CP

0 12/3/02 17/3/02 20/3/02 21/3/02 22/3/02 25/3/02

12/3/02 17/3/02 20/3/02 21/3/02 22/3/02 25/3/02

PM 3 PM 3 - Top side

PM 3 - Wire side

4000

4000

3500

3500

3000

3000 2500

2500 IGT CP

2000 1500

1500

1000

1000

500

500

0

IGT CP

2000

0 9/3/02 13/3/02 14/3/02 20/3/02 21/3/02 22/3/02

9/3/02 13/3/02 14/3/02 20/3/02 21/3/02 22/3/02

Mean Standard Deviation of Dot Area

Laboratory Offset Press (IGT) IGT Top side

IGT Wire side

4000

4000

3500

1 2

3000 2500

3 4

2000

3500 1 2

3000 2500

3 4

2000

1500

5 6

1500

1000

1000

500

500

0

5 6

0 PM 1

PM 2

PM 3

PM 1

PM 2

PM 3

Commercial Press (CP) CP Top side

CP Wire side

1 2

3000 2500

3 4

2000 1500

5 6

2500

3 4

2000 1500

1000

1000

500

500

0

1 2

3000

5 6

0 PM 1

PM 2

PM 3

PM 1

PM 2

PM 3

Appendix J

3500

3500

SD Dot Area IGT and CP

4000

4000

Appendix J SD Dot Perimeter IGT/CP (SD of mean SD)

Mean Standard Deviation of Dot Perimeter PM 1 PM 1 - Top side

PM 1 - Wire side

120

120

100

100

80

80 IGT IGT CP

60

60

40

40

20

20

0

CP

0 3/4/02

4/4/02

11/4/02 12/4/02 15/4/02 16/4/02

3/4/02

4/4/02

11/4/02 12/4/02 15/4/02 16/4/02

PM 2 PM 2 - Top side

PM 2 - Wire side

120

120

100

100

80

80 IGT CP

60 40

40

20

20

0

IGT CP

60

0 12/3/02 17/3/02 20/3/02 21/3/02 22/3/02 25/3/02

12/3/02 17/3/02 20/3/02 21/3/02 22/3/02 25/3/02

PM 3 PM 3 - Top side

PM 3 - Wire side

120

120

100

100

80

80 IGT IGT CP

60

60

40

40

20

20

0

CP

0 9/3/02

13/3/02 14/3/02 20/3/02 21/3/02 22/3/02

9/3/02

13/3/02 14/3/02 20/3/02 21/3/02 22/3/02

Mean Standard Deviation of Dot Perimeter

Laboratory Offset Press (IGT) IGT Top side

IGT Wire side 120

120

100

100 1 2

80 60

1 2

80 60

3 4

40

3 4

40 5 6

20 PM 1

PM 2

5 6

20

0

0

PM 3

PM 1

PM 2

PM 3

Commercial Press (CP) CP Wire side 120 100

100 80 60

1 2

80

1 2

3 4

60

3 4

40

40 5 6

5 6 20

20 0

0 PM 1

PM 2

PM 3

PM 1

PM 2

PM 3

Appendix J

120

SD Dot Perimeter IGT and CP

CP Top side

Roughness plotted against Standard Deviation of Dot Area y = 6E-05x + 3,6622

IGT Top 4,3

y = -1E-05x + 3,9889

IGT Wire

R2 = 0,0198

R2 = 0,0015

4,4

4,2

4,2

4,0

Roughness

Roughness

4,1

3,9 3,8 3,7

4,0 3,8 3,6

3,6 3,5 1500

2000

2500

3000

3,4 1500

3500

2000

2500

R2 = 0,0813

4,6 4,4 Roughness

4,0 3,8 3,6

4,2 4,0 3,8 3,6

3,4

3,4 1400

1500 SD Dot Area

1600

1700

1200

1400

1600

1800 SD Dot Area

2000

2200

2400

Appendix J

Roughness

y = -0,0003x + 4,3836

CP Wire

R2 = 0,1307

4,2

1300

4000

Roughness/SD Dot Area (trend line)

y = 0,0008x + 2,6358

4,4

3500

SD Dot Area

SD Dot Area

CP Top

3000

Roughness plotted against Standard Deviation of Dot Perimeter y = 0,0061x + 3,3504

IGT Top

R = 0,1171

4,3

y = 0,0011x + 3,8668

IGT Wire

2

R2 = 0,0042

4,4

4,2

4,2

4,0

Roughness

Roughness

4,1

3,9 3,8 3,7

4,0 3,8 3,6

3,6

3,4

3,5 50

60

70

80

90

60

100

70

80

y = 0,0026x + 3,7975

CP Wire

2

R = 0,1816

R2 = 0,0057

4,6 4,4 4,2 Roughness

4,0 3,8 3,6

4,0 3,8 3,6

3,4

3,4 40

50

60 SD Dot Area

70

40

50

60 SD Dot Area

70

80

Appendix J

4,2 Roughness

110

Roughness/SD Dot Perimeter (trend line)

y = 0,013x + 3,1182

4,4

100

SD Dot Area

SD Dot Area

CP Top

90

Appendix J Form Factor

Form Factor Laboratory Offset Press (IGT) IGT Wire Side

IGT Top Side

1,5

1,5

1,4

1 2 3 4 5 6

1,4 1,3 1,2 1,1

1 2 3 4 5 6

1,3 1,2 1,1

1,0

1,0 PM 1

PM 2

PM 3

PM 1

PM 2

PM 3

Commercial Press (CP) CP Top Side

CP Wire Side

1,5 1,4 1,4 1,3 1,3 1,2 1,2 1,1 1,1 1,0

1,5 1,4 1,4 1,3 1,3 1,2 1,2 1,1 1,1 1,0

1 2 3 4 5 6 PM 1

PM 2

1 2 3 4 5 6

PM 3

PM 1

PM 2

PM 3

IGT vs CP Top side

Wire side

1,5

1,5

1,5

1,5

1,4

1

1,4

2

1,4 1,4

1,3

1

2

3

4

5

6

1,3

3

1,3

4

1,3 1,2

1,2

1,2

1,2

5

1,1

6

1,1 1,1

1,1

1,0

1,0 IGT

CP

PM 1

IGT

CP

PM 2

IGT

PM 3

CP

IGT

CP

PM 1

IGT

CP

PM 2

IGT

CP

PM 3

Appendix J GL Sol

GL Sol Laboratory Offset Press (IGT) IGT Top Side

80 70 60 50 40 30 20 10 0

1 2 3 4 5 6 PM 1

PM 2

1 2 3 4 5 6

PM 3

PM 1

SD GL Sol

20

IGT Wire Side

80 70 60 50 40 30 20 10 0

PM 2

15

15

10

10

5

5

0

0

PM 3

SD GL Sol

20

Commercial Press (CP) CP Top Side

80 70 60 50 40 30 20 10 0

1 2 3 4 5 6 PM 1

PM 2

1 2 3 4 5 6

PM 3

PM 1

SD GL Sol

20

CP Wire Side

80 70 60 50 40 30 20 10 0

PM 2 SD GL Sol

20

15

15

10

10

5

5

0

0

PM 3

IGT vs CP Top side

80

Wire side

80

1 60

1 60

2

2 3

40

3 40

4

4 5

20

5

20

6

6 0

0 IGT

CP

PM 1

IGT

CP

PM 2

IGT

PM 3

CP

IGT

CP

PM 1

IGT

CP

PM 2

IGT

CP

PM 3

Appendix K Glossary

GL Sol Mean Grey Level and optical density in Solid area. Optical density is the mean grey level converted to a density unit. Too high grey value (too low print density) means a pale color and loss of contrast, however a too low grey level implies a loss of detail in the shadow areas.

SD GL Sol Standard deviation of Grey Level and optical density in Solid area. Indicates the print mottle, a low value points to an even print quality.

SD Dot Area/Perimeter Means the Standard Deviation of the Dot Area and the and are measured in mm2. Both indicators of print mottle (unevenness), a low value is desirable for both parameters.

Form Factor Form Factor = Dot Perimeter / (4pDot Area)1/2 The Form factor is the roundness of the dot. An exact round dot has the value of one and gives a perfect reproduction of the image. The higher value the poorer dot roundness.