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Question and Answer

Embossing Techniques

by Jeff Peterson

November-December, 1999
What are the issues to consider when deciding between combination and stamp & bump foil/embossing?

As most know, there are two ways to achieve a foil stamped and embossed image. You can either flat foil stamp the image and then come back and emboss it in register (stamp & bump), or have a combination die made and foil stamp and emboss the image in one pass. What is the best way? You would think that the answer would be simple-do it all in one pass! This is not always the case.

First, the length of the run has a major impact on your decision. If it is a short-run job, it may be difficult to justify the higher cost of a combination die, especially if the image is a single-level emboss. It is much less costly to have an etched flat stamp die and an etched single-level embossing die made. In addition, if the run is fairly short, having to run two passes on press does not add a great deal of press time.

Turn-around time can also be a factor when deciding between either option. A combination engraving will usually take much longer to produce than a flat stamp and etched embossing die. You may be able to get the dies for stamping and bumping the image the very next day, while a combination die could take 4 to 5 days or more. Again, the length of the run will help you make this decision. Another time related issue is the makeready on press. Foil stamping and embossing an image in one pass takes a perfect combination of heat and pressure to achieve the desired results. This can take a great deal of time on press. In addition, to maintain a quality foil and embossed image, a combination stamping usually must run quite of bit slower on press than either a flat stamping or embossing pass if you choose to stamp and bump.

If a coating or lamination is involved with the job, foil stamping and embossing the image may be your only choice. Laminating a foil and embossed image will flatten the embossing as it runs through the laminating equipment. To achieve the best results, you should fat stamp the image first, laminate the sheet next, and then come back and emboss the image. If the embossing is somewhat deep, you do need to watch that the lamination does not crack during the embossing process. Testing the sheets before running the entire job is recommended.

Lastly, registration is an issue when deciding between combination and stamp & bump. If you are using an older press that creates movement from sheet to sheet, then keeping proper registration when embossing a flat stamped image could be difficult. A combination die might be your best choice, especially if the foil/embossed image is not a tight registration to printing. If it is, you will have the same registration issues with either process.

InsideFinishing would like to thank Glenn Lovick of Independent Machinery (847-991-5600) for his assistance with this Q&A answer

What are my options to add color to an embossed image when using an embossing die only (not a combination die )?

Adding color to an embossed image when using an embossing die is not impossible. Many people do not realize that tint foils, available from most hot stamping foil suppliers, can be applied without the use of a combination die. Tint foils, unlike standard metallic foils, have a clear adhesive mixed with a translucent lacquer coat that allows the foil to apply a smokey or tinted look to the embossed image. It is an excellent way to add a hint of color to a sculptured embossed image, especially on a white stock.

If you are blind embossing an image on a medium to dark colored stock, you can add a burnished effect (known as glazing) to the embossed image. This is accomplished by increasing the heat and pressure slightly on press. The added heat will slightly discolor the stock and provide a very unique look to the embossed image.

What are my options when working with a multiple-up embossing job?

The obvious answer to this question is to use duplicates that are made from fiberglass-like material or a hard plastic, called Bakelite, that are readily available from many engravers. The original brass or magnesium sculptured engraving is duplicated several times to accommodate the number of embossing impressions needed on the multiple-up sheet. These types of Bakelite or fiberglass-like duplicates are an excellent choice for many applications, but do not have the durability of an original brass engraving.

An additional alternative to plastic type duplicates are duplicates plated with copper or nickel. Indianapolis Electroptype, Inc., has been producing these types of duplicates for over 80 years. A material called Vinyl-lite is placed on the embossing die and then is molded into the embossing image using heat and pressure. The Vinyl-lite mold is then sprayed with a liquid silver before being placed in an etching bath that "plates" the molded duplicate with a hard, durable copper. This duplicate method provides excellent heat distribution for high-speed equipment and excellent durability. These types of duplicates can be developed for embossing, combination, and flat stamping engravings.

A third option for multiple-up embossing applications is the newest technology in the engraving industry. H&M USA and Universal Engraving, Inc., and possibly others, have incorporated state-of-the-art programming with their engraving capabilities that will allow them to engrave brass engravings with CNC cutting technology. This means that the detail of an original embossing die can be programmed into a computer system, then additional brass duplicates can be engraved with a CNC cutting machine. This is an excellent choice for very long embossing runs because of the durability of using a brass engraving for each multiple-up embossing position.

CNC cutting is also an extremely precise method, ensuring that every engraving is exactly the same. And because the programming to cut the die is stored in a computer system, re‑ordering can be done easily and quickly as well. It is always a good idea to talk with your engraver when deciding on the type of duplicates to use. Time considerations and final costs can both be a factor in determining which type of duplicate is best for your application.