||Editing Profiles With Photoshop Adjustment Layers
Once you make a profile, or have one made for you, or when using the canned profiles that come with your printer, it is possible to edit the profile to change it and fix small areas you are not happy with. According to my friend Bruce Bayne, a color management expert, it is very common to have to make small edits to many of the profiles that are created. You will want to have this capability even if someone else makes a profile for you. Many of the profiles I have made were essentially good except for some minor flaw, like having a magenta cast in the 20% and 10% highlight areas. Monaco EZ Color 2.1, Monaco Proof and many other profiling packages now contain profile editors. These allow you to edit and improve a profile after making it.
Another technique Ive found to be very useful, and sometimes easier to use, is to just use the Photoshop Curves tool or Hue Saturation tool to edit your profiles. Lets say you create a profile, or have one made for you, and then test that profile with your images, or with the calibration image in the Chapter 15 folder on the Photoshop 7 Artistry CD. Say you find that the entire image has a green or magenta cast, it might be a bit too flat or contrasty or when looking at the gray swatches you may see a magenta cast in just the 10% and 20% swatches. For all these types of problems, you can often create a curve or Hue/Saturation adjustment, which will fix this problem. The steps to take are as follows:
1. Bring up my PS7ArtistryCalibrationImage.psd file from Chapter 15 on the Artistry CD. Leave it in ColorMatch space, don't convert it to Adobe RGB! Rotate it 90 degrees clockwise so its displayed correctly on the screen.
2. Go into Image/Image Size and turn off Resample Image and then set the Resolution to 375 Pixels/Inch. This will adjust the image to print on an Epson Letter size sheet. Arrange this original copy in normal screen mode at the top left of your screen and view it at 25% zoom factor. Change the window size at the bottom right of the window so this window covers the left half of your screen.
3. Choose Image/Duplicate to make a copy of the calibration image then drag the copy window to the right half of the screen. Choose Image/Mode/Convert to Profile to convert this test image from ColorMatch RGB into the color profile you want to tweak. I've done this to adjust the canned Epson profiles for my 7600 and 2200 so this calibration image printed with that profile (and my adjustments) matches this calibration image when displayed in ColorMatch RGB on my monitor.
4. My calibration image, the copy that is converted to your printer profile, should have already been printed on the printer you are testing using the print dialog suggestions on page 151 of Photoshop 7 Artistry. The top middle print dialog on page 151 is the setup you should use to print this test with Source Space: Document being set to the profile you are testing. Before comparing this print to your monitor it should have dried for at least 4 hours if printed with Ultrachrome inks and for at least two days if printed with Epson dye inks. This will allow your colors to stabilize. If you haven't already made such a print, do so now then come back to this after the print has dried for the correct amount of time or longer. Your monitor should be freshly calibrated and have been on for at least half an hour. If you just woke it up from sleeping, keep it awake for half an hour before doing these tests.
5. Open my calibration image and leave it within the Colormatch space and also in normal screen mode. When doing this, I usually view the image at 25% zoom factor. Choose Image/Duplicate to make a copy of my calibration image then choose Image/Mode/Convert to Profile to convert that copy into your printer profile. Arrange the two windows so the copy is on the right side of the screen and the original, still in Colormatch space, is on the left side. You need each window to take up about half of the screen and you need to be viewing the same part of the image in each window at the 25% zoom factor.
6. You should notice that the copy of my calibration image on the right, the one that has been conveted to the printer profile, will usually come closer to matching the test print than the original version in ColorMatch on the left. You should be viewing your print using a 5000K light source. Your first goal is to add Adjustment layers to the image on the right until it matches your print as closely as possible. These adjustment layers will not be saved.
7. Once the image on right of your screen looks like your print, you can now create yet another adjustment layer, or two, to modify the image on the right of your screen to make it look the way you really wanted your print to look. The way you really wanted your print to look is as close as possible to my calibration image when displayed like the image on the left of your screen which is still in ColorMatch space. Use the Save button in each color correction tool to save each of these last one or two adjustment layer settings.
8. Now make yet another test print starting with my original calibration image again but after step 3, after Image/Mode/Convert to Profile, create adjustment layers of the types and in the order used in step 7 and use the Load button in each color correction tool to load your saved settings from step 7 into each. After your test print dries for the correct amount of time, see if your adjustments improve the results. When you get the calibration image to look right, then you can use these same saved Adjustment Layer settings to adjust all your images for this printer, ink and paper. It will probably take you several tries to get the one that works for your. I made six tries when doing this on my 7600 but got the 2200 where I wanted it after only two tries. Practice makes perfect!
I've used these steps to tweak the canned Epson profiles for my 7600 and 2200 so the prints come very close to matching the screen and the prints from the 2200 are very close to the 7600 on the same paper. You'll find that there are always some images that don't match as well as others and you may need to tweak your tweaks for those images, which can easily be done after making small test prints of your images before you make a big print. On the 7600 I gang rows of 3 each 7.5" wide test prints together on the 24" wide roll paper. After check these out, I'll make larger prints which I sometimes have to slightly re-tweak. These saved Adjustment Layer settings are actually being used to edit the profiled image on-the-fly before making your print. I do this all the time to edit my profiles and you can try it without having to buy an expensive profile editor. You will need to make a set of these saved tweaks for each profile, but you can keep them in an appropriately named folder and just load them into adjustment layers when you need them. I've created actions to automatically convert to profile and load the correct tweaks for each paper/printer combination.