Preset Prepress Gamut Conversion

A whole series of RGB and CMYK color profiles are installed with Photoshop CS3, and you can also add your own custom profiles. Here is how you set up and use Photoshop CS3’s Color Settings dialog box. Note that this section provides recommended general settings for preparing an image to print in a standard commercial sheetfed print environment in North America. However, it is always best to ask for and receive specific setting values from your printing company. Follow these steps:
1. Open and make a copy of a print image that needs to be converted from RGB to CMYK. Name this image with CMYK at the end of the filename—for example, Alaska Light_CMYK, so you can tell at a glance that it is a CMYK file. Converting a copy will protect the color integrity of the original RGB image.
2. Activate the Color Settings dialog box (Edit ➢Color Settings or F/Ctrl+K).
3. If you see a More Options check box, check it to reveal…more! At this point, you can click the Settings menu to see a variety of preset settings available in Photoshop. Continue on to create your own settings for U.S. Sheetfed Coated offset printing.
4. From the Working Spaces RGB menu, choose Adobe RGB (1998). The default here is the limited color gamut Internet RGB color space, sRGB. Adobe RGB is a larger, more flexible color space in which to work.
Some printing companies prefer to use ColorMatch RGB rather than Adobe RGB (1998). If you are preparing an image for output at a specific printing company, select the RGB working space that they recommend.
5. From the Working Spaces CMYK menu, choose U.S. Sheetfed Coated v.2 to specify the CMYK color space for a typical sheetfed press printing in the United States.
Note: I am having you select this color profile as an example. The color profiles that are loaded with and available through Photoshop are some industry standard profiles. Some printing companies use these, others have their own profiles that they prefer for you to use. In fact if your printing company is color savvy, they can provide you with all their preferred setup values in this Color Settings dialog box. They may even have a Color Settings File containing values for this entire dialog box that you can load through the Settings
menu located at the top of this Color Settings dialog. A few enlightening minutes spent discussing the print companies preferences here can save lots of time and provide more dependable and better results.
6. From the Conversion Options Engine menu, choose Adobe (ACE). This specifies the Color Management Module (CMM) that will be used to perform the conversion.
7. From the Intent menu, choose Relative Colorimetric. This and Perceptual are both commonly used for this conversion. Avoid the use of Saturation or Absolute Colorimetric here for continuous tone images. Saturation mode is used for flat color images when the most saturated and consistent colors are sought, while Absolute Colorimetric is used for some proofing devices.
8. Enable the Use Black Point Compensation option. This will ensure that any dark black areas in your original image will print as dark black in your final print, rather than lighter shades of gray. Using black point compensation will help preserve the original contrast of your image.
9. Click the Save button to name and save this Color Settings setup as U.S. Sheetfed Coated Setup. When you create and save this custom setting, it will appear as a choice in the Settings menu. This means that you can easily recall this setting at any time. To learn how to create a custom CMYK color profile, skip ahead to the following section; otherwise, click the OK button to close the Color Settings dialog box.
10. After you have configured your Color Settings, you can choose Image ➢Mode ➢CMYK to convert your image from RGB to CMYK by using the CMYK color profile and settings you have assigned here. This RGB–CMYK gamut conversion can be recorded as a Photoshop action and applied to multiple images
by using the batch function.