Metallic or pigmented foils are applied on a letterpress using heat and a die.
A few tips when specifying foils:
- Most foils are opaque and will cover dark colors.
- There are a wide variety of foils: metallic (gloss, dull and machined), pigmented (gloss, dull or matte), pearlized, clear (gloss and full), patterns, and more.
- Metallic foils make a crisper impression than pigmented foils.
- An image can be foiled and embossed at the same time with a combination die, providing the embossing angles are not too steep and the entire image is foil stamped.
- Foil stamping does not work well over varnishes.
- Foiled elements that are too close may bleed together.
- Smooth or coated stocks work best with foil.
- The pressure and temperature of foil stamping can discolor some paper colors, especially browns, oranges and yellows.
- Test press proofs are recommended on large or complicated projects.
- Line (vector) art is required to make dies, preferably in Adobe Illustrator format.
- Avoid small or tightly-letterspaced type.
- Keep elements away from the edge of the sheet.
- As a general rule, the space between the lines in a design should be no less than half the thickness of the stock.
- Foil is not recommended on sheets that will go through a laser printer.
- Because foils are opaque, litho inks are normally printed first and foil applied afterwards.
- Applying foil to a varnished surface can be a problem.
- When combined with other processes, foil stamping is usually done last.