The Tricks of Trapping – BCM Inks


Ink makers are sometimes called upon to be magicians. I can’t tell you how many times we’ve been asked to make a blue ink when printed over a yellow not to turn the trap area green or pinhole. Or, we have a 4 color press but we want to run this 5 color job in one pass.

Impossible? No. Magic? I’ll leave the conclusion up to you.

If your ink maker knows the tricks of trapping, you can improve press speeds, improve press up-time or decrease press downtime, and improve appearance.

Ink trapping is defined as laying one or more inks over another. There are three types of traps- transparent , opaque, and screen. Each offers several benefits.

Transparent traps use clear or transparent ink to print in line over another color. The benefits are higher gloss appearance, improved rub resistance, improved trap, and options for additional colors. For example, trapping transparent yellow over blue yields green. A typical 2 color press could print 3 colors or a 5 color job might be able to be reduced to 4 colors. This saves press time and the need for an additional printing plate and ink.

Opaque traps use strong fillers like white and/or clay to cover or mask the previous down color. The benefits are improved hiding power, minimized washboarding, and improved color consistency.

Screen traps occur when the plate manufacturer screens all trap areas for optimal results. The benefits are faster drying, minimized shearing, and increased press speeds.

One other trick to trapping is monitoring your inks’ pH. You can prevent rewetting of the first down color by either staggering pH ( i.e. 9.2, 9.0, 8.8, 8.6) or using pH neutral inks (all pH levels the same).

Are we magicians? Sometimes. Problem Solvers? Definitely.

Learn how to trap one ink over another to produce the desired print outcome. Contact us. We can help you learn the tricks of trapping.