Printing and Design Tips: March 2012, Issue #128

What is “Transpromo” Material?

“Transpromo” is short for “transpromotional.” It is a subset of direct mail marketing that blends bill paying with advertising. You may have noticed these hybrid invoices, bills, or statements in your mailbox. Instead of being blank, what was once white space on the bills is now promotional material.

The big question is why? Why is this such a quickly expanding arena? The answer is simple. People actually do read their mail, and of all the mail they receive, they pay particular attention to their bills. With almost guaranteed visibility for their promotions, advertisers love this new venue.

There are other reasons for its popularity as well. Transpromo ostensibly costs nothing to mail. After all, the sender has already paid the postage for the statement, bill, or invoice en route to the recipient.

Another reason for the growing popularity of transpromotional material is the convergence of digital printing technology and database management. Companies can now collect and mine granular data on all their customers, data that go far beyond simple demographics. And with digital production, such as laser and inkjet printing, companies can personalize every page of every document that comes off press.

Furthermore, with the advent of the newer inkjet web (or roll-fed) presses, it is now possible to print an extraordinary amount of transpromotional material quickly (much faster than on laser-based equipment). And, as with other digital printing technologies, roll-fed inkjet presses can print 4-color images, which are more likely to attract readers, particularly when combined with highly personalized marketing information tracking prior purchases, personal interests, and so forth.

Direct mail marketers have even added QR (quick-response) codes to their transpromotional materials, so a recipient of this mail can scan the bill with a smart phone and immediately jump to a website for an even more personalized experience. The direct marketer can then collect more buyer information for their customer relations management (CRM) system via the two-way Internet connection, tracking, cataloging, and analyzing the information all the while.

What is Dimensional Stability?

Paper must be squarely trimmed to run correctly through a printing press. That is, all corners must be cut at right angles (90 degrees). This goes without saying, although problems occasionally do occur.

Beyond this caveat, paper must retain this consistency as it progresses through all aspects of production. Regardless of the humidity in the pressroom or the moisture content of the paper as it goes through the offset lithographic process, the dimensions of the press sheet in all directions must remain constant.

If a sheet can do this, it is said to have dimensional stability, and this markedly improves its “runnability,” or capacity to run through the press without incident, even before any ink touches the paper.

What is Picking?

Due to the cohesiveness of ink particles, ink on a press roller or blanket exerts a pull on whatever it touches. This is called ink tack. Ink deposited from the printing plate onto the press blanket pulls against the surface of the paper running through the offset lithographic press. If the tack of the ink is too strong (i.e., stronger than the surface strength of the paper), the ink tack will pull the paper apart by “picking” off fibers from the surface of the sheet.

Internal bonding strength refers to the strength with which a paper coating is fused to its body stock. The higher the internal bonding strength, the more the paper will resist the pull of the ink's tack and the less likely picking will occur during the press run.

Although you as a print buyer would not be responsible for the quality of paper bought by your printer, it is prudent when attending a press inspection at the printer's facility to look for signs of picking on the sample sheets that come off the press. Small white spots and flecks on an otherwise solid ink coating would indicate picking.

What is Wax Pick?

In order to ensure that paper received by a printing plant is within specifications, various tests can be run. To specifically determine whether high-tack ink formulations will be likely to pick fibers off the surface of a press sheet, the “wax pick” test is performed to evaluate the surface bonding strength of a press sheet.

A printer, packaging converter, or paper manufacturer might employ this test, which involves laying down successive wax coatings on the paper. Each wax is numbered according to its increased adhesive strength relative to the other coatings. By pulling the wax off the sheet, one can determine at what level of tack the printing ink will pick off paper fibers and coating particles.

In addition, the viscosity of the ink and the speed at which the press runs also influence ink picking.

What are Pinholes?

This paper surface irregularity is a flaw in papermaking, not a result of excessive ink tack. Pinholes appear when foreign matter gets on the paper surface during its manufacture, thus preventing the paper coating from being evenly spread on the sheet. This results in tiny holes or other imperfections on the otherwise even paper surface. While this does not show up often, a skilled pressman, packaging converter, or paper manufacturer can identify the flaw in samples of the printing stock.

[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.]