How come my blue is purple?

If you’ve ever labored over a full color page in your publication, only to see a blue sky appear stormy purple, well…we feel your pain. Color is something we work on every day, and we want to see your vision realized in print.

There is nothing more frustrating than finding out the effort you put in didn’t get the result you wanted–and understanding color a little better is one of the best ways to make sure YOUR blue STAYS blue.

The computer screen you view your publication on is based on one color model–RGB. However, the paper and ink professional printers print with are based on different color model–CMYK.

Why is this, and what does it mean to you?

Here are some great visual examples from wikipedia:

RGB_triangle

CMY_triangle

Note how the two images differ…

Do you see the how the center of the “RGB” image

is “white”?  This is because RGB,(which stands

for: Red Green Blue) is an addative color model.

Various portions of light wavelengths (the ROY-G- BIV acronym) combine to form visible white light.

Now when you look at the CMYK (Cyan, magenta, yellow, and Black–the “key” color or “K”) chart, you see that it is a “subtractive” color.
As you use portions of Cyan, Magenta, and Yellow ink, the colors block visible light from being reflected off of white paper–creating various shades of color.  As a result of blocking reflected light, a murky brown color is created if too much Cyan, Magenta / Yellow ink is used.

To help correct for this, black ink is added so that crisp dark colors can be generated.

But what does that all mean?

What it means to a publication editor is this:

Knowing which colorspace your text and graphics are in can tell you how their going to come out in print.  Here is an example from wikipedia:

RGB_and_CMYK_comparison

As you can see–the colors you generate with light are “brighter” than the corresponding colors generated by blocking light.

Does this mean all your images will look bad?

Certainly not!  You can improve the quality of images by making sure that you start in, or convert to to a CMYK color model.  You can do this a number of different ways (and you can call your tech support representative for details).

To begin with, LPi’s Art and Media Portal has several thousand images that are ready to go, formatted for CMYK. All you need to do is select the images of your choice, and insert them into the document! When working in CMYK, you’ll have a MUCH better idea of what your final product will look like.

A few tips to working in CMYK:

#1 use the smallest CMYK values you can to generate a given color.

CMYK values range from 0-100 for each of the four colors.  a cyan: 40 means 40% of the paper is covered in Cyan (light blue) ink.

However, once the ink hits the page, it gets even more interesting

Much like water soaks into a sponge, ink soaks into the paper–and while doing so, it expands.  This is called “dot gain”, as the ink “dots” get larger in size.

Since CMYK works by subtracting from the light that gets to your eye,  the more ink you use, the less light you see…and as a result,  less image.

#2 Don’t use less than 10% of a value.

When your colors go from your electronic file to our press, they are first sent to “plate” ( a flexible material which carries the ink information, and is placed in the press).  These plates register the ink “density” (11-100%).  Ink densities of less than 10% are unlikely to transfer visibly to the final copy.

#3 Use your color chart!

Your rep will know what format you print in (offset or digital), what colors you print in, and what pages have color. The color choices we show on the Color Chart are optimized for our process–if you want a green, for instance,  the numbers for “Green 356″ on your chart are a great starting point!

And questions?  Please ask your application support/tech support rep–speaking as one of them–we’d love to help out!

#4 Understand that “your mileage may vary”, and build your numbers to compensate.

The way your colors look on your screen (RGB) will look different than they do from the press (CMYK)–because of the color differences described above.  Thus, what looks blue on your screen might really BE purple in print, and if you change the numbers (with your new knowledge of CMYK, plus the help of your tech) you can compensate so you can make your blue sky “bluer”.
Your knowledge of color, plus the help of LPi’s technicians, will make small, key differences in the color values you decide on. Those choices can make a huge difference in the final product–and make sure your blue sky stays blue.

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