By now, many of you in the industry know what it takes to set up a color-managed workflow. The information has been discussed on the pages of this and many other industry publications. However, an understanding of the fundamentals, e.g. proper Adobe Photoshop settings, correct conversion techniques, use of a spectrophotometer and construction of ICC profiles will not be of much help if that last item, the ICC profile, does not exist.

If we are setting up a proofing system to simulate the output of the press, then a press profile is what we need. Unfortunately, the first step in creating a profile is to print the profile test target, a document usually larger than 8.5-by-11 inches in size, containing more than 1,000 color samples. It is difficult for many to justify the cost of a press run to produce such a target on a sheetfed, let alone a web press. Enter the pseudo-profile.

Small target, improved results

A pseudo-profile appears, for all intents and purposes, to be a traditional ICC profile. Its key feature is the target needed to build it, which can be .25-by-3 inches or smaller that contains a mere dozen color samples.

It’s hard to believe that space can’t be located somewhere on a representative press run to tuck away such a minute target. The trade-off for using such a small target with an equally limited sample set is, not surprisingly, decreased accuracy.

A newspaper should never attempt to produce contract quality proofs using a pseudo-profile. Instead, these profiles can be used to simply move closer to the final output. If I can’t have complete accuracy, I’ll settle for closer any day.

Target samples

The target needed is shown in Figure 1. As you can see, it is nothing more than a combination of color samples you might find on a traditional color bar. At a minimum, you will need 100 percent patches of cyan, magenta, yellow, and black. For better results add 100 percent patches of red, green, and blue.

Fig. 1: This simple target can help to improve your proofing accuracy.

Finally, if you are really feeling adventuresome, add 50 percent patches of cyan, magenta, yellow and black. Using your preferred measuring device, measure and record the L*a*b* values of each of the 100 percent solid colors and the amount of dot gain in the 50 percent patches. In addition, measure a clean, non-printed area of your printing stock. Next, it’s on to Photoshop.

Adobe Photoshop is certainly not considered to be an ICC profile building package nor is it intended to be. It does have a trick, however, hidden deep inside the Color Settings panel for the construction of very simplified profiles.

Begin by going to Edit>Color Settings, click on the CMYK drop-down menu in the Working Spaces section and select “Custom CMYK…” located at the top of the menu (see Figure 2, page 32).


  Fig. 2: Begin building your Profile by selecting “Custom CMYK” from          
  the Photoshop Color Settings panel.
 

On this panel, click on the “Ink Colors” drop-down menu in the Ink Options section and select Custom (see Figure 3, page 32).

  Fig. 3: Selecting Custom allows you to enter specific data about
  your specific inkset.
 

To complete the information needed for this panel (see Figure 4, page 32), begin by checking the “L*a*b* Coordinates” checkbox in the lower left-hand corner. Next, enter all of the L*a*b* values you recorded earlier.

  Fig. 4: Here you will enter your L*a*b* values into the appropriate boxes.

If you do not have overprint values to enter, input the 100 percent cyan, magenta, yellow, black and paper values and check the “Estimate Overprints” box in the lower left-hand corner. Once the values are all entered click OK.

Back in the Custom CMYK panel, enter the amount of dot gain you measured from the 50 percent patches (Figure 5). If the amount of dot gain for each color is not equal, you can select “Curves…” from the drop-down menu and enter the amount of dot gain on a per channel basis.

  Fig. 5: Enter the specific separation and dot gain information or use
  these values as starting points.

Under the Separation Options section, select settings you know to reflect your actual press conditions or start with the settings shown in Figure 5 and click OK.

Return to the Color Settings panel. Click on the CMYK drop-down menu and select “Save CMYK…”(Figure 6) and then give it a descriptive name and save it wherever profiles live on your system.

  Fig. 6: Save CMYK allows you to save your data entries as an ICC profile.

You now have a simple ICC profile based on the actual ink colors you use on press and incorporating other press characteristics such as dot gain. You are not finished yet, however.

Taming the wild pseudo profile

At this point, the profile you built will be fairly useless. (You didn’t think it was going to be that easy, did you?) To be useful, this profile will need to take a trip or two through your favorite ICC profile editor. I’ll be covering profile editors in the next installment (see Newspapers & Technology, September 2007), so if you don’t already have one, watch for that article.

First, we’ll be editing the white point. Even though you entered the L*a*b* values for your paper stock, this entry in the resulting profile is regularly incorrect.

Re-enter the L*a*b* values to correct this. You can use your editor to correct for any additional deficiencies you detect once you test your profile. That is the beauty of this simple profile; it is fully editable.

These profiles tend to work best in CMYK workflows, where incoming images are already in a CMYK working space such as SWOP. You can use your profile to produce a soft proof on your monitor or as a simulation profile for making a hard-copy proof on your inkjet or other proofing device. The hard-copy proofs tend to be more accurate although in all cases you will find that you can increase the accuracy through additional editing of the profile.

Clearly, a full profile target correctly printed and measured will give you far superior results than will a pseudo profile. But when you are unable to print such a target the above technique will still allow you to improve the quality of your proofing output.

John Nate is a senior color specialist for Chromaticity Inc. He can be reached at 616.361.7773, or via e-mail at jnate@chromaticity.com.