User Guide

Prepress Fundamentals 75
PageMaker 6.5 Advanced  2002 Cheltenham Computer Training
FOR USE AT THE LICENSED SITE(S) ONLY
 Cheltenham Computer Training 1995-2002 - www.cctglobal.com
Trapping
© Cheltenham Computer Training 2002
Adobe PageMaker 6.5 - Slide No 30
Trapping
• Trapping refers to when
you apply a slight overlap
of colors in order to stop
any spaces from
happening while printing -
just in case paper shifts,
stretches or plate
misalignment occurs.
1. Green is Chocked to Trap
the Red.
2. Red is Spread to Trap the
Green.
3. No trapping used.
12
3
Using
Trapping
Terms
• Trapping - applying a slight overlap of colors in order to stop any
spaces from occurring while printing, in case a paper shift, stretch or
plate misalignment occurs. The principle is that trapping is applied to
a piece, based on how an object's color blends with the background
color of another item.
• Overprint - mixing colors by printing a colored object in the
foreground prints completely over a colored object in the background.
This is used when black is the foreground color
OR
if you want to intentionally mix colors to create a new third
color.
• Knockout - removing a colored object in the foreground from the
background color to stop the inks from overprinting. This can cause
a gap between the foreground and background color edges, and
trapping will close the gap.
• Spread - a method of trapping used when colors are knocked out
and the foreground color turns out to be lighter than the background.
The foreground color object has its edges enlarged a little bit to have
the foreground color spread out into the background color when at
press.
• Choke - a method of trapping used when the foreground color is
darker than the background (opposite to the Spread method). The
background color object has its edges reduced a little bit to have the
background color spread into, or choke, the foreground color.