How to Make Color Separations in Illustrator

by eHow Computers Editor

If you are sending your artwork to a printer, you will need to produce color separations. Printers divide colored artwork into four plates: cyan, magenta, yellow and black (often referred to collectively as CMYK). The process of dividing the artwork is called color separating. The films made from the plates are called separations. These instructions apply to Adobe Illustrator 8. Procedures for other versions may vary.

Calibrate your monitor. Consult your instruction manual for help if needed. By calibrating, you match (or attempt to match) the color seen on screen with the printer's outputted color.

Compare colors in your artwork before and after the calibration.

Select overprint options for any colors that you want to be transparent. Fills and strokes in Illustrator appear opaque and knock out the color beneath. Overprinting prevents this from happening. Choose Overprint Black under Color in the Filter menu.

Create a trap to compensate for misregistration on the press. Misregistration causes gaps to appear between overlapping colors. By creating a trap, you prevent this gap from appearing. To create a trap between two simple objects, select the topmost object, then using the Stroke palette (choose Show Stroke under the Window menu), set the stroke width to somewhere between 0.6 and 2.0. Display the Attributes palette from the Window menu and check the Overprint Stroke.

Set the printing bounding box and the crop marks.

Set separation options. Choose Separation Setup from the File menu, then set options. Click OK.

Print separations.


  • check It is a good idea to work closely with your print shop when making color separations.
  • check Artwork can consist of spot colors, process colors and registration colors. Process colors are the four inks used in color separations (cyan, magenta, yellow and black). Spot colors are premixed colors that are used instead of or along with the CMYK inks. Registration color is that which is typically used for crop marks and trim marks.
  • check You can use a special trapping program such as TrapWise to create your traps.

Items you will need