Four (full or process) Color Separations

It helps to understand the printing process when learning to create full color ads.

Offset Printing

Printing presses apply color to paper using various colored inks. Four process color inks are printed on top of each other in varying patterns to created a full color image. The colors are Cyan, Magenta, Yellow and Black (CMYK - where "K" is black). Each color is applied to the paper separately. The colors are carefully aligned, or registered, in the proper position to produce a final image.

Each color applied to the paper requires a separate "plate". The cyan information is output on one plate, the magenta information on another, and so on.

Specifying Color in Software Applications

In contrast to spot color, process color can be applied in a variety of ways, either by using named colors (PANTONE for instance) or just picking color from a software application's color mixing palette.

Applications that will allow you to do this include: Adobe InDesign, Adobe Photoshop, Adobe PageMaker, Quark Xpress, Corel Draw, Macromedia Freehand and Adobe Illustrator. Files can be saved in JPG, TIF, PDF or EPS format.

It is important to realize that four-color printing does not have the color range that using PANTONE spot colors would give you. Bright or fluorescent colors cannot be simulated using process color. Colors are approximated as closely as possible.

Other Specifications

Although four-color printing is possible with low resolution art, the results are poor. It is important to start with high resolution graphics when making the extra investment to print in full color. 300 dpi or better (at the actual size the image will be used in) is the rule to follow when creating art for a full color ad. The file sizes will be dramatically larger.