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Production Techniques 2

This segment is the second in a three-part series that will
discuss areas of production where the design of a piece
directly impacts cost, quality, and the overall success of the
job.

Avoid Knock Outs
When stamping a piece that has been printed, it is best to
stamp over the ink instead of knocking out the image to be
foil stamped. Metallic foils are completely opaque, so it is
unnecessary to knock the image out. Trying to hit the exact
mark every time in perfect registration is an impossible task.
Because every press has a slight amount of movement,
creating a piece with the images knocked out is creating a
registration nightmare. The answer? Simply print the entire
piece and over stamp the images, making sure that the
correct inks and coatings are used.

Build in Trap
Situations do exist when an image needs to be knocked out.
For example, when stamping a piece with foil that is not
completely opaque, such as with a pearl or pigment foil. If
knock out is necessary to maintain color integrity, then it is
imperative that appropriate trap be built into the design, just
as with printing. Trap, as far as foil stamping is concerned, is
defined as fattening up the foiled image so as to allow for a
small amount of overlap onto the printed area, thereby
accounting for slight variances in registration. The amount of
trap that should be built into the design can depend on
several variables, including size of the image, type of the
font (i.e., serif vs. sans serif), and even the type of die used
– as some will expand more than others. However, as a
general rule of thumb, the amount of trap should equal at
least .020” or approximately 1/64.

The verbiage on the left has had the text knocked out during
printing. When the foil was stamped over the printed area
the registration was slightly off, allowing the paper to show
around parts of the foil. Since most foil is non-transparent,
knocking out the foil area is unnecessary and potentially
disastrous to the project. The verbiage on the right has not
been knocked out and the finished piece will look good even
if the registration is slightly off.