Printing & Design Tips: SEPTEMBER 2006, #62

What is a Perfecting Press?

A perfecting press is a press that prints both sides of a sheet in one pass. A web press (roll-fed press) is always a perfecting press because the roll of paper only travels through the press once, and both sides of the sheet are printed as the paper flies through it. A perfecting web press is commonly used to print newspapers.

In the sheetfed arena, a two-color press that can perfect may print black on both sides of the sheet, or it may print a PMS color on both sides of the sheet. It may also print different colors on the two sides of the press sheet. The key is that both sides are printed at once.

This process becomes particularly useful on a multi-unit press, such as a ten-color sheetfed press. Such a press can print four process colors on each side of the sheet at the same time plus a varnish or a PMS color on each side as well. A good choice for such a press would be a sixteen-page process-color booklet (eight pages on each side of the press sheet receiving four colors as the sheet passes through the press). Your pressman will not need to print one side of the sheet, wash up the press and change the plates, and then “back-up the sheet” (print the opposite side of the sheet when the first pass is dry). The whole job can be printed at once. This will save time and money. However, not all printers have such elaborate presses.

On a perfecting sheetfed press the pressman usually (but not always) can change the color configuration, and various presses allow for a number of different variations. A six-unit press, for instance, can print four colors on one side of the sheet and two colors (two of the same colors as are printed on the other side of the sheet or two different colors) on the back of the sheet. Or the press can be configured to print three colors on one side and three on the other, or five on one side and one on the other. You could also print six colors on one side (perhaps four process colors, a dull varnish, and a gloss varnish) and then print the back of the sheet when it is dry in whatever fashion you choose. Keep in mind that while these are the potential color configurations, not all perfecting presses can be set up to accommodate all of these options. Work closely with your printer to design the most efficient way to print your job on his particular press.

What is the Difference Between a Form and a Signature?

Imagine that you are on a press inspection. Your printer pulls a sheet from the press and hands it to you for your approval. It has four pages across the top of one side of the sheet and four more pages “in-line” immediately below. When the back of the sheet has been printed, and the sheet has been folded and trimmed, you will have a sixteen-page booklet (made from a flat press sheet with eight pages on the front and eight pages on the back).

Technically, the flat sheet the printer hands you contains one “form” on either side of the sheet (i.e., eight pages on each side). When the form has been folded and trimmed and the pages are in readable, consecutive order, that booklet is a “signature.” Of course, your entire job (a perfect-bound book, for instance) may be composed of ten or twenty of these signatures, stacked on top of one another and then bound.

What is Foil Stamping?

When you want a flashy metallic effect in a solid area or perhaps a rule surrounding an invitation to make it stand out, what are your options? You can use a metallic ink. However, metallic inks become dull as they are absorbed into the paper during the offset process, and they also tarnish as they oxidize just like certain types of jewelry.

Another process you can use to get a metallic effect is called hot foil stamping. A metal die is made for use in a letterpress (a press for relief printing, in which the printing surface is raised above the non-printing surface). For instance, you might foil stamp a company logo (let’s say the image of a bird above some type). The die hits the foil, punches out a portion of foil the shape of the bird and the type, then lays it against the paper as the press operates. Heat and pressure attach the foil to the substrate.

This process affords a bright, shiny, dense, metallic surface. You have a wide variety of options to choose from that include gold, silver, colored metallics, pearlescent, marble, and geometric patterns. The list goes on.

Keep in mind, however, that since you will probably also offset print a portion of the job, foil stamping will probably require an additional pass through a letterpress. In addition to spending several hundred dollars for the die-making, you will need to factor in the cost of the foil and the extra cost of the letterpress. This is a specialized, expensive process but one that yields a very distinctive and attractive product. Foil stamping could be the focal point of your piece.

[Steven Waxman is a printing consultant. He teaches corporations how to save money buying printing, brokers printing services, and teaches prepress techniques. Steven has been in the printing industry for thirty-three years working as a writer, editor, print buyer, photographer, graphic designer, art director, and production manager.]