First Design Guide - Flexographic Technical Association

3.1.2 Process Color Type
When identifying colors for text copy, the designer should be aware which colors will be built from process and which
will use dedicated spot colors. In general, text copy should be printed with a single color or built from two process
colors. As text size increases, a third process color may be introduced. Using more than one color to create text should
be discussed with both the prepress and print providers to determine capability.
3.1.3 Process Reverse/Knockout
A holding line should be used when type is
reversed and comprised of more than one
color. The holding line should be a single, dark
color to hide any slight misregistration that
is likely to occur during the printing process.
The weight of the holding line should be
twice the registration tolerance for the print
segment as identified in Table 3.1.1, Total
Trap Tolerance. Because the values provided
are general guidelines, the designer should
confirm the trap requirements with the
prepress and print providers.
If a holding line is not used, the darkest or
predominant color should be made at full size
and the remaining color must be choked back
the width of one row of dots as determined by
the screen ruling. If possible, the background
color should be limited to one color.
3.1.4 Line Reverse/Knockout
Reverse copy should be limited to one color. If copy is to be reversed from two or more colors, a holdback or choke
must be created for register. Refer to Table 3.1.1 Image Trap Tolerance and the specific print segment. Because the
values are general guidelines and print system dependent, the designer should confirm the trap requirement for reverse
text with the prepress and print provider.
3.1.5 Drop Shadow
If a drop shadow is abutting another color, it
will need to trap. Be sure to move the drop
shadow by more than twice the specified
image trap for the appropriate print segment.
Refer to Design Section 3.1.1 for segment
specific guidelines on total trap tolerance.
It is best to use only drop shadows for larger
type, unless the color selected for the type is
darker than the color it is abutting; remember,
these abutting colors will be required to
overprint each other to form the image trap.
FLEXOGRAPHIC IMAGE REPRODUCTION SPECIFICATIONS & TOLERANCES
NOT SUPPORTED BY FIRST:
Reversed type without a holding line or
lighter color choked back will result in
misregister and legibility problems.
FIRST RECOMMENDED:
Reversed type with holding line – the
weight of the holding line should be
twice the image trap tolerance.
FIRST RECOMMENDED:
Reversed type with magenta choked
back to allow for trap tolerance.
DESIGN
PROPER IMPROPER
S. Gilbert
3.1.5: Drop Shadow: If inappropriate image trap tolerances are applied (such as using
offset traps on a flexo job), objectionable type will result.
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