Linearization and Profiling notes. Overview:

Step 1. Set printer properties Step 2. Linearization process. A. Reduce CMYK ink channels. B. Linearize ink channels. C. Set total ink limit. D. Check linearization. (optional) E. Check for neutral grey. Optional. Step 3. Create ICC using profiling software. Step 4. Save ICC with Wasatch linearization.

Begin. Step 1. Set Printer Properties. Select ‘None’ for the imaging configuration on the “Set up” window in Wasatch. Set printer properties using Print/Set-up/Edit/Properties. Select ‘OK’ to save your settings and to name your Imaging Configuration. Step 2. Linearization Process. (also see special notes at the end of this doc for CMYK ink limiting) A. Ink reduction in each individual ink channel. Three different methods *. *Use your eye to determine where to reduce each CMYK individual channel by locating the patch in each channel where the ink seems to be reaching 100%, with no increase in density thereafter. This is an easy fast way to reduce ink, but is subject to your judgement and viewing conditions. (Use linearization file from C:/psfiles/generaltest018eye One.)

*Or you may use a loop to look at the actual dots of ink to determine where to reduce ink. Using a loop may assist you in determining the patch where you are getting the best dot coalescence without any printing artifacts.

*Or, a third method for reducing ink is by using a densitometer. Select, Print/Setup/Edit/Color Transforms/Calibration/Calibration Curves/Densitometer. Scan in the CMYK patches. (The density values may be viewed on the “Original” tab). We will NOT be using the actual densities to calculate the ink reductions, but instead the difference between each density and the next. Examine these differences starting from 0 to 100%. Subtle patterns in these differences will reveal a “knee” or radical change point where each channel has reached a maximum dot coalescence. (see below)

(The process above may be simplified using Excel. After scanning the CMYK channels, click ‘OK’ to save this data and give it a name such as ‘Densitometry Values May9’. Next, open these values in Excel. In Excel, select: File/Open: C://WWrip67/ Configurations/ Select your printer name/ Select your “Densitometry Values May9” file/ Open the “densitometry calibration curves” file.

Next, choose the parameters to open the file: Select “delimited”.

Next: Select “space”.

Next: Select “decimal separator”.

Next: Select “finalize” to open the densitometry data. Next: Select and copy the complete column of your “Densitometry Values May9” data in column “B”.

Next, paste the data into column “B” of the “Tabulate_Calculation” .xls Excel file provided to you. The doc “Tabulate_Calculation” will complete the subtraction of the density values. The results will be shown in column “D”. The ‘maximum dot coalescence’ will be demonstrated by the ‘radical change point’ in the differences. This ‘change point’ will also be shown in the curves (100% on the left, 0% on the right). Use this information to select your individual ink channel reduction.

Now begin making your profile starting again with ‘None’ in the Set-up window, and make the ink reduction of your CMYK channels using your desired method (Visual, loop, or density). (Note: If your customer wants “stronger color” in their final profile, it may be necessary to select an ink reduction value that is slightly higher than this ‘radical change point’ for each channel. So, you must make a new profile adding, for example, 5% additional ink in each channel, and then completing all the steps again). For variable dot printers, make your ink reduction in Print/Set-up/Edit/Color Transforms/Calibration.

For fixed dot CMYK LcLm printers, always make your ink reduction using Print/Set-up/Edit/Color transforms/Halftone Properties. You MUST check “Fixed Dot Ink Reduction” for fixed dot printers. Checking this tool will apply algorithms in Wasatch that will automatically reduce the LcLm inks in a calculated relationship to the CM channels.

B. Linearization. Rip and print the “general test018eyeOne.ps” file again using your applied ink reductions and now read in the CMYK patches using the Calibration/Calibration Curves in the Color Transforms screen.

After reading the patches with the Eye One, click OK, and you will see the curves for the channels you have read. Click OK again to apply linearization, and continue clicking OK until you are asked to save this step to the profile you are making.

C. Total ink limit. Print out the 0-400 CMY total ink patches. (general test018eyeOne.ps). Determine your total ink limit by using a loop to examine the black composite ink patches. Choose a total ink limit value where you no longer see any bleeding between the black composite patch and the cmy/rgb colorants around the black patch. Enter this value in the Color Transforms screen Total Ink Limit tool. (Or you may set the Total Ink Limit in your profiling software, and leave Wasatch at 400).

D. Check step. (optional) Do a check to see if you are linear. In this ‘check’ step, (since you already have linearized) print and scan your CMYK patches to then view the linearized curves. Make sure to CANCEL after you view your linearized curves. You do not want to save this ‘check’ step over the top of your linearization that you have performed already above.

Step 3. CREATE ICC You will now use your profiling software (such as Monaco, Profile Maker, or Eye One Match) to generate the patches for your ICC. It is best to use about 1500 patches. Save these to your desktop. Open them inside of the Wasatch “Layout” window. Print them from Wasatch using your linearization from the steps above. Scan the ICC patches using your profiling software. Click ‘Next’ to begin creating the ICC. When the ICC has been created, save it to your desktop. Step 4. You will next open the Color Transforms screen in Wasatch and Browse your desktop for the ICC.

Click OK and save the output ICC with your linearization and give it a final name. You are now finished. Modification. (see below).

Modification. You may easily modify your finished profile by changing the input profile on the Color Transforms screen. For example: an input profile of CMYK_plus30 will give you stronger color from your output profile.

You may also modify your output profile by making a different selection of “Rendering Intent”. For example: the “BPC” rendering intent will stretch the gamut for your black point and give you more rich blacks in your raster image.

Special notes for CMYK ink limiting: Color = Light Color is not the ink. Ink is only a filter of light. No ink = all light = all color.. 100% of CMY = black = no color. I must see the media (light) to see color. Media = light. To control color, I must control how I see media behind the filter of my ink. Special ink limiting: C ------------------------------------M ------------------------------------Y --------------------------K --------------------------------Y takes away total ink space from CMK, and will produce orange/red. K will also take away total ink space from CM. “Almost” always, K should be less than CM. “Almost” always, Y should be less than K. K should “almost” always be equal, or less than CM. Y should “almost” always be equal, or less than K.