"The Ins and Outs of Stamping and Embossing Dies"
[Column #39, 3/98]
Since we're winding down the annual report season, I'm reminded of the incredible impact of embossing and debossing in the printing process. Consumers today are inundated with messages in nearly every form-it takes a lot to grab their attention. Embossing and stamping are traditional finishing techniques that still have that kind of power.
Annual report season brings added headaches to the bindery because designers everywhere want to use these specialty finishing techniques and don't consult us ahead of time. We are constantly battling printers who want samples tomorrow for a job they believe requires a simple single-level die. Wrong. If you want that superfancy design with all sorts of bevels, textures, and levels, a lot more is involved. Such jobs require extra planning, money, and time-all of which are rare commodities in this industry! I tell our customers, "Call us ahead of time. We want to be involved from the very beginning. Believe me, it helps everyone involved-a lot." With all that in mind, I am dedicating this article to the basics of embossing dies (and to whining).
First, a quick reminder, embossing simply means altering the fibers of paper to create an image area raised above paper level. Debossing alters the fibers to create an image area below paper level. A blind emboss occurs when there is no printing or foil on the embossed area, while a register emboss is designed to emboss in register to a printed image. During the embossing process, an etched metal female die encounters the upper surface of the paper and is met with a male counterdie on the lower surface of the paper. In debossing, the genders of the dies are reversed. All these images are created using stamping dies, heat, and pressure.
Embossing dies are generally composed of one of three materials-magnesium, copper, or brass. When to use which is determined by the intricacy of the design, the size of the job, and the desired life of the die. While magnesium is the least expensive type and provides quick turnaround time, it cannot achieve the detail and precision necessary for more complex images. Mag dies are typically used for short runs as they tend to smash out and break down fairly quickly. They are used in both embossing and foil stamping. Most flat foil stamping jobs are done with mag dies. In addition, they are typically last longer on smooth stock because textured stocks act as an abrasive and can chip at the die and wear them away.
Copper dies are moderately priced, are photochemically etched, and work well with designs that exhibit fine lines and detail. They have significant lasting power, should be used in foil stamping, and can also be used in embossing. Copper dies have a much longer life than mag dies because they are not affected by oxidation. For these reasons, we use copper dies frequently.
The Cadillacs of embossing dies are made of brass. They produce sharp, clean images and are great for intricate designs. In addition, brass dies can be used for more than a million impressions. Because these dies require hand-tooling, the cost is typically higher than for copper or magnesium. The bevels on a brass die are sharp and clean and can be sculptured if desired. Brass dies are rarely used in foil stamping. With proper care, they can last indefinitely.
This is where a lot of the miscommunication begins. Just what types of images require elaborate handwork? When a customer shows us some knock-your-socks-off example of embossing created with multilevel, sculptured dies and says, "I want mine to look just like this" (and this happens frequently), we know we're in for some educating. For intricate designs that require special effects such as sculpturing, sharp bevels, or texturing, a brass die is necessary. Brass dies can take several weeks to produce because of the handwork involved and are more costly as a result.
To further complicate the issue (and confuse the customer), myriad dies are available based on the type of design being used. Following are the most commonly used dies:
Single-level die: An embossing or debossing die that changes the surface of the paper at one level.
INSERT GRAPHIC: SINGLE-LEVEL DIE (#1)
Multilevel die: A die with a number of distinctive levels. It can be engraved by machine and does not require hand-tooling. Multilevel dies are often made of brass.
INSERT GRAPHIC: MULTI-LEVEL DIE (#2)
Bevel-edge die: An embossing die with a precise bevel on the image edge, usually between 30 and 60 degrees. The broader the angle, the greater the illusion of depth. Very deep dies must have beveled edges to prevent cutting through the paper.
INSERT GRAPHIC: BEVEL-EDGE DIE (#3)
Sculptured die: A hand-tooled die, usually made of brass, which embosses many levels through the use of curves, angles, and varying depths. For example, this type of die would be very effective for embossing the image of a rose.
INSERT GRAPHIC: SCULPTURED DIE (#4)
Stamping die: A die, photochemically etched, that is used for flat foil stamping. It is commonly made of magnesium, except when longer runs or larger images are necessary and copper is used instead.
INSERT GRAPHIC: STAMPING DIE (#5)
Chisel die: An embossing or debossing die with a V-shape, using two bevels without a flat bottom surface. It is most frequently used in debossing.
Rounded die (domed die): An embossing die that imparts a rounded configuration to an embossed image. It is commonly used for logos and typographical effects.
Combination die (foil emboss die): A specially constructed die, usually brass, that allows embossing and foil stamping to be accomplished in a single impression.
In keeping with my motto, "Call us ahead of time!" there are many considerations in any embossing job that can mean the difference between an affordable, great-looking piece and an out-of-control, second-rate piece.
Paper stock is a big issue. For an embossing design with a lot of precise detail, coated stock usually works best. However, if the embossing height is great (depths can vary from as little as 0.006" all the way up to 0.024" on a single-level die), an uncoated stock may help avoid cracking. For deep embossing without much detail, we recommend a highly textured or long-fiber uncoated stock.
The layout of the job is also imperative as it can affect the number of passes required to complete the job. This is a big issue when it comes to money and time costs. Remember, too, what embossing will do to the other side of a sheet. Avoid small print or detailed art in these areas and understand these areas will be dulled and discolored due to heat and pressure. Another bindery tip-registration is extremely important. Don't cut off the gripper and side guides-think of this process as another color in the printing process. Also, be sure to ask your finisher how to prepare your artwork for ordering dies (e.g., type size and weight). Specifications vary depending on the design. Find out what works best for your job.
With the onslaught of multimedia applications, I'm heartened by the knowledge that these traditional specialty finishing techniques have not only maintained their place in the printing community, they are growing in popularity-now if we could only come up with a way to get the jobs done efficiently.