Color Spaces Part 2

This is a continuation of the topic of Color Spaces started in the previous post.

Photoshop Gamut Warnings, continued

(These recommendations are for images intending to print in CMYK.)

Along with your monitor and your printer, a photo has its own color space. It may fall completely inside both the RGB and CMYK color spaces, or it may be mostly within both spaces with only a few areas out of the CMYK gamut (like the sample photo below, also used in the previous post), or it may have large areas unavailable to a CMYK gamut.  To refresh your memory, here is our sample photo with gamut warnings turned on in Photoshop.

If your photo is like ours, with very few areas of gamut warnings, it will probably look just fine in CMYK when it is converted from RGB to CMYK for print. You may want to tweak it a little, but it should look fine. Below is a comparison of our original sample image in RGB, the image with gamut warnings turned on in Photoshop, and the what the image looks like converted to CMYK. Not a lot of difference.

However, if your image has large areas covered in Photoshop's gamut warnings, you should make adjustments before you submit your image to print, otherwise you could be disappointed in the difference and you won't be in control of the effects of color conversion.

Most of the time the problem and its solution lie in the over-saturation of colors. So create an adjustment layer for Saturation in your image.

Then choose the channel in which the most warnings show (if it's in a grassy field, choose the green channel, if it's someone's red sweater, choose red, etc.)

Adjust the saturation down, until many or most or all of the gamut warnings disappear.

Another option is to create a Levels adjustment layer, and use that instead to adjust colors to remove some of the gamut warnings.

Minimizing these gamut warning areas now will minimize color shifts when your image is converted to a CMYK, or print, color space.

Before converting your image to CMYK, know what your Conversion Options are set to in your Color Settings menu. (Control + Shift + k to open the Color Settings menu in Photoshop)

Overall, we recommend that the "Intent" be set to "Relative Colormetric." For a detailed explanation of what these four rendering intents do, please visit this informative tutorial here.

This tutorial does a good job explaining the difference between Photoshop's four rendering intents: Perceptual, Saturation, Relative Colormetric, and Absolute Colormetric. And it will help you know when it's a good idea to use one of the other options besides Relative Colormetric.

(It's also a good idea to know what your other settings in the Color Settings menu are set to, as well, but we aren't covering that, right now.)

Now your conversion of an image from one color space to another will be less surprising, whether you convert your image in Photoshop, or you let your print provider do the conversion from RGB to CMYK in their workflow.

Why All This Matters to You

This is really all about control. If you know what is happening to your image's color space as you move from RGB to CMYK, you can better control how it looks. And you don't leave that control in the hands of others.

As you design your print projects, keep in mind the differences between the RGB and CMYK color spaces, or gamuts. Because they are different, what you see on your monitor will not necessarily represent what you see on paper, and what you print out on your inkjet or color laser printer does not necessarily represent what you will get from your print provider.

In fact, without any controls in place, it is a sure thing that they won't be the same.

Remember that each device has it's own color gamut. Each monitor, printer, and press will display or print your image slightly differently from your monitor, your printer, and your print provider's press.

This is one reason why the proofs that a print provider give to you are so important. The color proofs from your print provider should show what you can expect your images to look like when printed. Here at Lorraine Press we've put a lot of effort into making our color proofs an accurate reflection of what you will see on our presses at the press check.

Also, when working in cross-media marketing campaigns, knowing about color spaces and how they basically work can help as you choose colors that can look good for your projects in any medium — especially if you are using web and print in your campaigns.

Hopefully, if there are any readers still out there reading what has to be one of the longest blog posts I've ever written, this has helped introduce what color gamuts are and how they affect your projects.