CMYK - digital printing FEATURE

Ask a Smartpress.com Expert: Subtractive & Additive Color

Ask a Smartpress.com Expert: Subtractive & Additive Color

I’ve been a web designer for years and now I want to do more print work. I think I need a little help, as the samples don’t quite look right – they’re too dark. What can I do to make sure the colors that I’m working with on the screen appear on the paper prints?

- Color Cautious

As you’ve noticed, the colors that you see on a backlit screen don’t always translate directly to print. This is because colors are dependent on the medium with which a designer is working, whether you’re painting with a computer mouse or a paintbrush. Colors in digital images are created with an additive color model, while painting, digital printing and other related art forms use subtractive color model to create different hues.CMYK - digital printing

Subtractive color models start with a white canvas and a limited set of paint pigments, inks, dyes or other colorants that are mixed to create a wider range of colors. When all of the colors are combined in equal amounts, black is the result, which you can see in the diagram to the right. It’s called “subtractive color” because though it seems like color is being added to a colorless base, the resulting hues are created by absorbing (or subtracting) some wavelengths of light and not others. The color displayed depends on which parts of the visible spectrum are not absorbed and remain visible. CMYK is a subtractive color system, so our CMYK digital printing process is subtractive, too.

RGB - digital printingAdditive color models are the reverse. They start with black and as more color is added, the hues get lighter until you get white, as can be seen in the diagram to the right. It’s called “additive color” because all of the colors must be added together to create white. This system is more attuned to how the human eye detects color and isn’t simply a result of absorbed wavelengths of light. RGB is an additive color system, so the colors that you see on your computer monitor (or TV screen) are additive, too.

So you can probably see where the colors are being lost in translation. You’re designing in an additive color space (your computer screen) and want your designs to be reproduced in the subtractive color space (on paper). Not only are you trying to translate between two color systems, there is a distinct possibility some elements of your design will not make the color conversion. That’s because though a monitor can display millions of colors, even the highest quality digital printer may only be capable of producing thousands of colors. What we see is not always what is possible to get.

There are ways to make the translation easier, however. Working within the CMYK color system in Adobe Photoshop, InDesign or Illustrator can give you a good start towards ensuring color accuracy from the digital space to the digital print. Of course, that goes along with saving your file in the CMYK format. Choosing colors from Pantone palettes can also insure proper color rendering. You can try to calibrate your monitor for better color accuracy and order a color reference chart from the Smartpress.com presses to compare our print to your monitor. But the best way to get an idea for what your print project will look like would be to order a hard copy proof.

Once you receive a hard copy proof, you can make adjustments to your digital file to produce the colors that you want. If the colors you need are very specific, you may need to order more than one hard copy proof. But once your proof looks right, you’ll know that your digital print project should be just as you expect it.

Have a question about online printing that you would like to have answered? Leave your question in the comments below or email us at customerservice@smartpress.com and we will do our best to answer your questions.

About Jill Alfano

Jill Alfano, mother of two, loves musicals and gardening. She has 12 years of prepress and printing experience in digital, offset, flexo and screen printing.