Have you ever designed a layout that includes blue only to find when it goes to the printers the colour prints as purple or pink. This is because in the CMYK process some blues that look blue on the computer screen tend to print purple. Also, the lighter the blue, the more purple it gets. For example, a blue gradient that starts with a deep blue will more than likely start to turn purple as it gets lighter. Also if you use the 100% blue in Quark you are likely to end up with a purple-looking colour in CMYK because the levels of magenta it contains are too high. Many people get around this by using a Pantone colour blue that will print as you see it on screen. I also find that a blue with the following values seems to print correctly. C 100 M 65 Y 0 K 0.