What does “spot” color mean in offset printing? It means that each color in an offset print project is printed with it’s own ink. For instance, let’s say you’re printing letterhead where the logo is green and the rest of the type is black: In offset printing we would use black ink and a green ink. Offset printers use the Pantone Matching System (PMS) to mix specific ink colors.
An analogy to spot color printing would be when you’re painting your walls in your home. You decide you want s specific paint color and you go off to the paint store and they mix tints into a bucket of paint for you.
In order to achieve many colors, it’s impractical to mix an individual ink for each color. In “process” color printing, also referred to as CMYK or full color printing uses four spot colors, cyan, magenta, yellow and black, hence CMYK (yes, black is K!). In offset printing, by varying the amount of each of the four inks on a sheet of paper, just about every possible color can be achieved.
How do you decide which process to use? In general, if your offset printing project contains just a couple of colors, it would be more cost effective to print individual spot colors. A project containing color photos or many colors would be printed using the four primary ink colors, cyan, magenta, yellow and black. In general, if your project contains any more than 3 spot colors, it’s usually preferable to print CMYK.
There are other considerations of course, such as the way the artwork is constructed. Your offset printer can advise you as to what process is more cost effective for a particular job.
{ 2 comments… read them below or add one }
Thanks for making this sound easy (I appreciate the analogy for non-printers like myself). The whole process seems less intimidating now and I can approach my projects with more confidence. I look forward to additional, informative articles. How about visual aids in the future that help broaden the picture for printing process ‘newbies’ like myself?
Thanks for your comments. Adding graphics is a good idea. We’ll try to incorporate them in future posts.