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avoiding paper pitfalls

Jun 1, 2002 12:00 AM


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Who knew that baseball pitchers and binderies face the same challenges? The Colorado Rockies recently announced a new scheme to cut down on home runs: The team is storing its baseballs in a temperature-controlled chamber to prevent them from drying out. According to one sportswriter, the idea is to make the balls easier for pitchers to grip and harder for batters to hit out of the ballpark.

Similarly, postpress operations are trying to get a better grip on some slippery substrate issues. Many binderies have been the victim of poorly conditioned paper, which caused lost time, profits and customers. And, today's coated paper is harder to get a grip on, since it contains a much higher percent of clay and other fillers.

Fortunately, this month we have called on this industry's equivalent of ace relief pitchers. These postpress pros have some useful tips for avoiding paper problems when diecutting, folding, coil binding, perfect binding, UV coating and digital printing.

DIECUTTING

To reduce spoilage and improve turnaround times, consider stock thickness and moisture content, says Bob Windler, president of Diecrafters, Inc. (Cicero, IL). Diecrafters is a 55-year-old company that does diecutting, finishing, stamping and embossing jobs, in both short and long runs.

KEEP PAPER THICKNESS UNIFORM

Never mix paper weights, brands or lots — at least not without telling your finisher first, Windler advises. When a job varies in stock thickness, diecutters must accommodate the thickest stock in a production run, which “causes a chain result of problems,” the exec explains. Thinner stock will end up being cut too hard, causing sheets to fall apart. Windler says machine operators then need to add more nicks to hold the sheets together, “but this has the undesirable effect of adding too many unsightly, rough edges.”

DRY DOESN'T WORK

“Brittle, dry stock tends to fall apart,” observes Windler. “As you can probably guess, this requires more nicks.” Dry stock also reportedly affects scoring quality, because the fibers in dry paper aren't as pliable and are more susceptible to cracking. The exec adds that some paper finishes are more difficult to work with than others. Uncoated stock tends to run better and require fewer nicks than coated stock, for example. And laid stock often appears to crack, adds Windler, even after steel-rule scores are applied. Controlling heat and moisture during the printing process will help combat these problems.

If you have the extra time and money, Windler notes that any project-appearance problems from nicks in the paper can be minimized by allowing for a re-trim area. Nicks may also be sanded away after the diecutting process has been completed.

FOLDING

ODD LOTS

Be careful of running odd lots of paper, warns Jack Rickard, president of Rickard Bindery (Chicago). Even within a uniform paper lot, there still may be variation in paper bulk: For example, 80-lb. uncoated cover stock can caliper anywhere from eight to 13 pts., depending on the manufacturer. Why does this matter? According to the exec, while 10-pt. stock usually folds well, paper 12 pts. or thicker requires different folding techniques and machines. If you do change paper in the middle of a job, make sure to mark where the change occurs and advise your bindery.

Half of Rickard Bindery's 80,000-sq.-ft. building is dedicated to folding paper. Services include miniature, oversized, map, gate and specialty folding; 12-pocket saddlestitching; loop stitching; seam, fugitive and remoistenable gluing; rotary scoring; personalized product handling; fulfillment; wafer sealing; and automatic shrink wrapping.

PRESCORE THICKER STOCKS

In general, the thicker your stock, the more variables you will face, according to Rickard. He advises prescoring stock if it is 100-lb. text weight or heavier. Thicker stocks without critical color breaks can reportedly sometimes be inline wet- or folder-scored, but the exec suggests getting a second opinion before bypassing diecut scoring.

Also, watch for ripple cracking on buckle folders when folding stock thicker than 10 pts., advises Rickard. Thick sheets reportedly can fracture as they bend around the rollers, though Rickard observes that knife folders generally will not ripple-crack the stock.

BEWARE OF THE FIBERS

Paper fibers can break during folding, resulting in cracking. But Rickard says jobs can often be saved by choosing proper fold plates, machines and production techniques. According to him, the shock load on paper fibers increases geometrically with machine speed — slowing down your folder reduces fiber stress and can eliminate the problem.

COIL BINDING/PUNCHING

“Punching into copy is an easily preventable, but all too common problem,” observes Brenda Slacum, COO at Specialties Bindery (Hyattsville, MD). Before you commit ink to paper, ask how much margin your bindery needs to clear your punched holes. In general, she says, most 3:1 (three holes per linear inch) Wire-O projects require a ⅜-inch spine margin. For 2:1 Wire-O books bulking more than 0.5-inch thick, Slacum suggests allowing at least a 9/16-inch margin.

Specialties Bindery offers high-volume and specialty binding services, including mechanical binding, such as Wire-O, spiral wire, plastic coil and plastic comb; perfect binding; rotary scoring and more.

KNOW THE BULK OF YOUR BOOK BLOCK

Books bulking 7/16 inch or thinner can be bound with 3:1 wire, according to the exec. Books bulking thicker than 0.5 inch requires 2:1 wire. “If you lay out your text with a ⅜-inch spine margin and then use a 2:1 wire, you will punch into type,” she explains.

LAYFLAT ADHESIVE AND PERFECT BINDING

Adhesive issues can, not surprisingly, arise with poor-quality paper, notes Chuck Cline, president of postpress consultancy Binding Solutions LLC (Stockton, NJ). Look for these factors:

PAPER GRAIN

Cline says a printed sheet being bound cross-grain is a particular challenge. “It's like holding five pencils in one hand, about an inch from the bottom,” says the consultant. “Anyone can pull those pencils out of your hands. But if you turn the pencils 90 degrees and hold them from the top, it's much harder for them to come out of your hands.”

Unfortunately, economics play a big part in whether a sheet is bound cross-grain or long-grain, says Cline. “If printers can get more pages by turning the paper 90 degrees and printing it that way, they're going to do that. But it does make it tougher for the binder,” he says.

HIGHLY COATED, GLOSS OR MATTE COATED PAPERS

These papers are particularly difficult to bind when they're above a 60-lb. basis weight, according to the exec. PUR adhesives are reportedly effective at binding these stocks, but they are more expensive and involve specific handling. (For more information, see “Almost perfect,” April 2002, p. 46.)

Frank Shear, president of Seaboard Bindery (Woburn, MA), observes that some binderies that offer layflat-adhesive binding actually shy away from jobs that use coated stock, but concurs that binding on these projects is often successful if the text stock grain is parallel to the spine and PUR is used on the spine.

Seaboard Bindery offers perfect binding, layflat and polyurethane reactive (PUR) adhesive binding, saddlestitching, collating, cutting, folding and shrinkwrapping services.

AMOUNT OF RECYCLED FIBER IN THE PAPER

Adhesion to recycled paper is poor because the recycled fibers are shorter than non-recycled fiber. Thankfully, Cline says there's a limit to the amount of recycled fiber being put in paper, as manufacturers have discovered it detracts from paper quality. Also make sure there's a higher percentage of fiber in the paper than clay fillers, says Cline. “People try to buy 60-lb. paper, but if it's 80 percent clay, there's not much paper fiber for the adhesive to hold on to,” he warns.

Overall, “make sure you're using good-quality paper” when perfect binding, advises Cline. Check the paper's poracity, flexibility, amount of coating and the basis weight. As always, keep in mind some layout rules of thumb when planning jobs, Shear adds. Layflat-adhesive binding can reportedly accommodate books up to 1.5 inches thick or more.

UV COATING

TEST PAPER IN ADVANCE

According to Mark Beard, president, Finishbinders, Inc. (Des Moines, IA), porous stocks absorb UV coating, resulting in diminished sheen and durability. Virgin papers, on the other hand, “have been known to develop a yellow tint after coating,” he says.

Finishbinders, Inc. is a full-service trade bindery. Services include UV coating, laminating, box and pocket-folder converting, perfect binding, saddlestitching, polybagging and other services.

BE AWARE OF PRESS POWDER

“Sometimes excessive press powder can cause UV coating to have a granular, or sandpaper-like, feel,” relates Beard. He adds that jobs with too much press powder add time to the back end of production: “Finishers get poor production rates because calendar rollers need to be cleaned — sometimes as frequently as every 15 minutes,” he says.

DIGITAL PRINTING

According to David Clark and Frank Romano, authors of “The Very Last Designer's Guide to Digital, On-Demand and Variable-Data Color Printing,” dry-toner presses take most of the moisture out of paper. Papers dried out in the digital-printing process and bound against the grain may later swell against the grain, become wavy and buckle at the spine when exposed to normal humidity conditions.

The authors suggest trying to rehydrate paper by letting it set in an area of “sufficient humidity.” They warn, however, that wavy paper that has been dried for more than 72 hours will remain that way. “A temperature- and humidity-controlled environment is essential,” they note.

“The Very Last Designer's Guide to Digital, On-Demand, and Variable-Data Color Printing,” from PIA's (Alexandria, VA) Digital Printing Council and GATFPress (Sewickley, PA), costs $35 ($25 for PIA and GATF members). To order, visit www.gain.net.

Reader input wanted

What are your biggest postpress paper problems? How have you resolved them? Write us at APeditor@primediabusiness.com, and tell us your paper woes — and solutions.