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 overstamp 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.
Reprinted with permission from the Foil Stamping and Embossing Association (FSEA).
Dennis Bacchetta
Diamondessence™
Packaging
