Saturday, March 19, 2011

Color separations for printing.

So, yesterday I had another "professional designer" (for questions about why the quotes are here, view my first post below) submit a file for printing. I placed the file into InDesign to set up the press sheet and viewed the Separations preview to verify that all colors were correctly called out and the file was good to print.  Sadly, that's a no on this file.  This happens all too often... almost daily... sometimes hourly : (

As a designer, setting up a file to print on a desktop printer or being posted to the web is really easy.  It's similarly easy to set things up for printing, but it's important to keep in mind the process when doing this.  When a file is created using, say, three colors that will be going on a traditional offset press, it's critical to be sure that those three colors are appropriately color-coded in the original document.  This may seem like an easy thing to do, but it's regularly not done.

I think it's important to understand where a graphic design element or project will be used prior to creation.  For instance, I regularly see logos that are created in Photoshop, then the customer sends me a 21K JPEG that they want placed on their 6' x 3' outdoor sign.  Remember, VECTOR, VECTOR, VECTOR when it comes to logos.  With today's modern vector graphics programs there isn't too much that you can't do in a vector drawing program.

So, with the project yesterday, the artwork was vector, all colors were appropriately set up, were this project to be going on our full-color press, but that isn't the case. They have specific Pantone colors they want to use and unfortunately, some colors don't match exactly in a CMYK printer versus a custom-mixed Pantone color.  There's an excellent color theory article that explains these terms in more detail - here's a bit of it:

As you might suspect, there are different types of color. Now is when you can throw the color wheel out the window.

RGB Color: This is color based upon light. Your computer monitor and television use RGB. The name "RGB" stands for Red, Green, Blue, which are the 3 primaries (with green replacing yellow). By combining these 3 colors, any other color can be produced. Remember, this color method is only used with light sources; it does not apply to printing.

CMYK Color: This is the color method based upon pigments. "CMYK" stands for Cyan, Magenta, Yellow, and Black (its what the K stands for). Using these 4 colors, most other colors can be achieved. Unfortunately, CMYK cannot reproduce the same amount of colors as RGB can, which is why yellow-greens sometimes look a bit muddy when printed.
This is the method used by printers the world over, and is also a clever way of mixing paints.

Pantone (PMS) Color: This is yet another printing color method. PMS stands for "Pantone Matching System," and is a large list of specially mixed colors made by the Pantone Corporation. Instead of using CMYK to create colors, the pigments are created individually for purity.
For example, if I wanted to use a Red-Violet color, I'd pick PMS 233M. The color would be made exclusively for my project and would always print exactly how I want.
The only drawback to using PMS colors is that they're only useful for projects with few colors. They're also expensive.

Ford, Ryan. "Color Theory: A Brief Tutorial." Color Theory: a Brief Tutorial. 2007. Web. 19 Mar. 2011. <>.

1 comment:

  1. Thank you so much for sharing.........
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    Green Printing