Also called hot-die stamping, foil stamping is a method of letterpress printing using a stamping die, heat/pressure and metallic or pigmented film.

Foil stamping differs from both engraving and embossing in that it uses a die with its image area in relief; that is, standing up form the surface of the plate.

In hot stamping, an extremely thin ribbon of foil is fed into a press, it releases its pigment onto the paper when pressed between a die and a hard flat surface and heat is applied. A combination of heat and pressure then bonds the leaf material to the paper.

Here are the keys to success when using this technique; plan ahead and follow a few basic guidelines.

• Nearly all foils are opaque and generally useful for overprinting dark colors or where reflectability will add a graphic image. White foil is in great demand due to the inability of the offset process to print in opaque white ink in a single pass. In addition, a hot stamping technique can be applied to foils to offset or varnish printing surfaces provided the varnish or offset ink is of the non-wax variety.
• Avoid combination dies that contain steep angels because they impair efficient bonding of the foil to the paper when the foil stretches to fit the design is too intricate; don’t put elements to close together.
• If the design also includes varnishes, plan carefully. Although the process is well suited for coated cover papers, foil stamping does not work well on varnished surfaces.
• To get maximum use of the materials used, remember when designing the piece that a foil-stamped border will waste a lot of material compared to a self-contained image.
• Foils may also be stamped over one another.
• Many opaque pigmented foils may be hard to cut cleanly during stamping. Whether used flat or in combination with embossing, foil stamping provides a highly unusual effect to any graphics project. The finisher’s expertise is a great asset; so, get in touch early in the design process.

Foil Types

The decorative and useful process of foil stamping has been around longer than the printing press. With the incredible selection of foils available, the possibilities seen endless, and a foil stamp adds a truly refined look and feel to any piece.

• Metallic: Gloss, Dull and Machined.
• Pigmented Metallic: Gloss and Dull.
• Dusted Foil
• Pearlized
• Clear: Gloss and Dull
• Marble, Oil/Water Shimmer, Etc.

These are particularly useful for overprinting on dark paper stocks, as nearly all foils are opaque. In addition, there are pastel foils, marbled foils, and dusted foils that give a softer image. The foil you select, of course, depends on the effect you are trying to achieve.
Because of their high reflectance, foils are particularly suited for pieces that need to stand out and catch the eye-such as the covers of a paperback books and annual reports.

Pastel leafing

Pastels, or tint leafs, offer a subtle alternative to brighter metallic, as do some of the pearlescent effects now offered. The tints, when used in combination dies, eliminate registration problems that occur when trying to emboss a pre-printed pastel image.

Pastel leafing is a hot stamping technique that is perhaps the best way to give shadings and toning to blind embossing.

Because pastel leafing adds the most color to the lowest point, it adds depth and definition to the design. For this reason, pastel leafing is generally used with sculptured or multi-level embossing.

• Pastel leafing can be done with existing dies by shops that do hot foil stamping and embossing work. It poses no particular problems, but requires a good die, the proper heat and pressure, a sufficiently heavy stock and a workable design.
• Adding this effect is about the same price range as single color printing once you have invested in the die. This makes it an economical choice when you want to accent a small, intricate embossed design with a subtle color contrast.
• Color choices are, however, somewhat limited. The leaf material-either a matte-finished or a pearlized pigmented foil-comes in pastel shades of blue, pink, green, peach, yellow, gray and clear. The clear leaf adds a touch of glossy finish to a flat sheet.

The most out of the process

• Leaf stampers can pull samples of leaf or foil color o paper you have specified using any die thy may have on the press.
• Don’t design elements close together. Foils tend to “bridge” across narrow spaces.
• Avoid tight kerning and fine type (i.e. super condensed), they will fill in with foil.
• Stamping too close to the edge of a sheet without bleeding off the page may cause wrinkles or puckers.
• When using combination dies, the entire embossed image must be stamped. To stamp just the highlights of an image a separate press run is necessary.
• Foil can be used over lithography and vice versa, but special lithographic inks are required.
• Foils are repelled by heavy offset sprays, inks containing waxes, silicone or plastic and varnish.
• Avoid combination dies that contain steep angles because they impair efficient bonding of the foil to the paper when the foil stretches to fit the design. The foil effect can backfire if the design is too intricate; don’t put elements to close together.
• If the design also includes varnishes, plan carefully. Although the process is well suited for coated cover papers, foil stamping does not work well on varnished surfaces.
• To get maximum use of the materials used, remember when designing the piece that a foil-stamped border will waste a lot of material compared to a self-contained image. The finisher’s expertise is a great asset; so, get in touch early in the design process.

Stamping limitations

Hot stamping involves certain limitations for which the designer should be aware:

• On certain colors of stock, especially browns, yellows and oranges, the temperature and pressure in foil stamping can discolor the paper.
• You are limited in matching foil to Pantone colors.
• Pigmented foil colors may appear slightly darker or lighter, depending on the color of the background. It is strongly advisable that you check with your printer early in the design state.
• ”Dropouts” in a solid ink background require hairline register of foil stamping.
• When using stamping with other processes, stamping is done last.
• Envelopes are converted after stamping only if an impression of the image is objectionable on the back of the envelope.
• The foil stamper has the capabilities for proof testing for additional cost.

Improving your designs

• Experiment with different combinations of foils (i.e. foil on foil, clear foil over four-color lithography).
• In some cases, more than one color can be stamped in a single impression. Consult your foil stamper before designing.
• Metallic stamp “cleaner” than pigments.
• Pastel leafing works best with sculptured dies.
• Printing on foil is another exciting effect; that is when flat stamped foil is overprinted in one or more transparent or opaque ink colors by regular offset printing.
• Foil can be used over lithography and vice versa.

NOTE: halftones of not greater than 150 line screen are recommended and specially formulated offset inks should be used.

• Foils are repelled by heavy offset sprays, inks containing waxes, silicone or plastic and varnished papers.

Evaluating proofs

• Check for feathering, color changes, scuffing and peeling.
• Stock should be sufficiently covered by pigment.
• Edges should be sharp and crisp.

Preparing the artwork

Clean line art file

Illustrating comps

• Metallic pens or glazed paper can also be used to simulate leaf/foil stamping.