A colour bar is a sequence of solid, halftone, and overprint color patches positioned in the trim area of a press sheet. Press operators use it in conjunction with a densitometer or spectrophotometer to measure ink film thickness, dot gain, and color registration across the width of the cylinder. It ensures that the ink keys are adjusted correctly and the color remains consistent throughout the print run.
Check the colour bar on the tail edge of the sheet, the cyan is running a little heavy on unit two.
Also heard as
- color bar
- control strip
Related terms
CMYK
The standard four-color printing process that combines cyan, magenta, yellow, and a key plate of black ink.
Cropmark
Fine lines printed outside the artwork area that indicate exactly where the paper should be cut.
Bleed
An extra margin of printed image that extends beyond the final trim size of a page.