Perfect Binding Technology Follows the Digital Flow

by: James Tressler, C.P. Bourg, Inc.

Nothing has changed the face of perfect binding technology faster or more completely than the digital technologies used to create, prepare and print pages.

Page layout and text editing software, digital photography and image editing, Internet distribution, job prep, and short-run digital printing – all are powerful forces pushing the limits of what can be perfect bound. In turn, perfect binding technology has risen to meet these market challenges with advances in products, processes and adhesives that will spur the market to bind more – and more kinds – of books better, faster and less expensively than ever before.

The technologies underlying these changes have been at work since the 1980s. But it is only recently that we have reached a tipping point, where market forces spurred by the convergence of multiple digital technologies all of a sudden seem to have quickly and conclusively leapfrogged traditional binding methods.

The Commoditization of Print

For example, the market for on demand book publishing is soaring. Bowker1, the official International Standard Book Number (ISBN) agency for the U.S., recently projected that 285,394 titles were produced in the U.S. in 2008 on demand, a “staggering” 132 percent increase over the 2007 total of 123,276 titles. Equally startling, the 2008 level reflected the second consecutive year of triple-digit growth in the on demand segment, rising 462 percent above 2006 levels.

Based on the preliminary figures from U.S. publishers, Bowker said 2008 could prove to be a “watershed year” in which titles produced on-demand and short-run – which it defines as print runs of less than 100 – exceeded the number of traditional book titles entering the marketplace. And that’s before adding consumer and corporate titles that often escape ISBN classification.

Data gathered for the Printing Industries of America Digital Printing Council2 bear this trend out:

  • Between 1980 and 2007, the number of commercial publishers mushroomed from 10,000 to nearly 95,000.
  • During that time, the average number of books per order dropped from 18,963 to 3,055.
  • By 2007, 30 percent of all books published were printed digitally.
  • From 2000 to 2007 the publishing market grew almost 50 percent, from $21 billion to nearly $33 billion.

Clearly, book run lengths are collapsing while the number of titles – and the overall market – is expanding, if not exploding. Consider the experience of Tennessee book manufacturer Lightning Source, Inc., which claims that from its inception in 1997 to 2008 it delivered more than 50 million books on demand with an average run length of 1.8 copies.3

This evidence is not surprising when you consider that books printed digitally don’t need to be inventoried or warehoused, never go out of print, can be produced on demand in whatever quantity needed, and can be requested, sold, and distributed through more channels.

Digital Impact

The trend toward digital is reflected in diverse ways – from the business habits of corporate enterprises looking for ways to showcase their image or streamline their operations, to the increasing numbers of “micro publishers” and vanity press, to average consumers flooding printing e-tailers with requests for a few photo books of the family vacation.

Digital printing has unique characteristics that significantly affect binding and finishing technology:

  • Dramatically shorter runs. Although average run length is between 100 and 300 copies, books of one are commonplace, as evidenced by the experience of companies like Lightning Source, Shutterfly, Snapfish and Lulu.
  • Different processes. Unlike offset inks, which are absorbed into the paper’s fibers, digital inks and toners in effect are less durable coatings placed or fused onto the surface of the paper.
  • Different papers. Digital production increasingly involves color ink or toner printed on coated, double-sided (C2S) covers and coated text stocks of varying weights.
  • Different sizes. Even though digital formats are smaller than offset (at max 14.33 x 22.5 inches), their range is optimal for one-up page production and adequate for 2-up and 4-up production of longer-run, smaller format documents.
  • Collated output. The bindery needs to keep digital output in sequence or risk ruining an entire output stack.
  • Variety. Digital printing is able to print any number of books and pages one after another on demand for almost any purpose imaginable – from college course packs to corporate histories, product manuals to weekly in-store shopping guides, and photo books to family genealogies.

The Internet also is exerting influence by making it possible to sell, accept, track, arrange to ship, and bill jobs electronically. Meanwhile, the more challenging economics of the past decade have translated into generally higher costs for everything from labor and energy to storage and shipping – everything except for printing, which has become a commodity.

Finishing Just in Time

So, what do these trends have to do with binding and finishing in general, and with perfect binding in particular?

For print buyers, print on demand is more efficient, less costly, and lower risk. With digital printing, economies of scale are largely irrelevant so there’s little reason to produce more copies than needed – a boon for companies trying to eliminate storage costs. The resulting phenomenon of smaller runs and just-in-time manufacturing to avoid overstocks and remainders is being repeated at publishers, retailers, and corporations across the country.

Meanwhile, consumers as comfortable handling computers and digital cameras as they are a perfect bound copy of National Geographic or a John Grisham paperback now see the practicality of instant self expression in self-publishing photo books and family genealogies.

With the commoditization of digital printing and consumer demand on a collision course, the bindery is emerging as a “value added” service – whether it’s found in a corporate, commercial, or trade setting. The bindery able to offer “finishing on demand” offers something they never had or needed before: opportunity.

Within this context, perfect binding has emerged as a familiar, quick-turnaround, professional-looking bookbinding method that has a future as bright as a camera’s flash.

Nimble Equipment and Automated Processes

What’s new in perfect binding technology to meet these market challenges?

The fast pace and individuality of digital printing technology demands equally nimble binding and finishing technology. The biggest beneficiaries are systems able to bind or finish documents efficiently in short runs from one copy to several hundred.

On-line variations following the debut of the Xerox DocuTech actually emerged before off-line units. The first on-line signature booklet maker (the C.P. Bourg SBM-1) was introduced in 1990; the first single-clamp perfect binder (Bourg’s BBF2005) appeared in 1995. On-line systems are matched to the output from the digital printer and by definition are fully automated to allow a single person to operate the print and finishing operation. Since then, a number of off-line single-clamp systems have appeared.

With print run lengths tumbling and experienced help harder to find, automated job setup and changeovers are important features for any binder, but they’re critically important for systems used for producing short-runs, and especially books of one.

On these systems, computer technology married with advanced mechanical engineering techniques have produced systems capable of automatic operation such as milling and jogging, and measuring the thickness and length of each book block both to determine glue application and automatically center covers of different sizes one after another. Touch-screen terminals with icon-driven operating menus for fast and easy job setup are now the norm, and job changeovers have evolved beyond the need for adjustment tools.

Rounding out the equipment advances are closer attention to operator ergonomics and safety features that keep hands safely away.

Aggressive Adhesives

Polyurethane reactive (PUR) adhesive is the big story here. A tenacious, hot-melt, solvent-free adhesive that reacts to moisture in the air, PUR is resistant to a wide variety of inks, varnishes, oils, and solvents, as well as temperature extremes, and handles lay -flat applications with ease.

Although PUR was developed in the 1980s, the technology was recently reformulated, making it better suited to quickly and aggressively bind the coated stocks and delicate inks and toners used in color digital printing. Reformulated PUR pull-strength and flexibility is superior to other adhesives. And even though full strength is reached in eight to 24 hours, books bound with the new PUR formulation can be trimmed within two minutes and shipped the same day. In short, PUR is perfect for binding longer-life books that use heavier weight, larger size, or specialty papers and have heavier ink or toner coverage.

The more aggressive PUR adhesive requires a sealed glue tank to prevent unwanted contact with moisture in the air and a tightly controlled precision delivery system, both to prevent premature curing and to avoid waste and cleanup associated with misapplication.

PUR also is more expensive than other adhesives. Pound for pound, polyvinyl acetate (PVA) or ethylene vinyl acetate (EVA) can bind almost twice as many books as PUR. However, because PUR is more effective for binding color digital printing smothered with toner, inks, or fuser oil and “knits” much better to the fibers of coated papers, it allows the bindery to charge considerably more per bind.

What’s in Store for the Future?

With short runs increasing, look for automation to affect every aspect of binding and finishing equipment, as well as binding and finishing workflow. For off-line production, content and cover-driven workflows will gain prominence. And with demand for PUR on the rise, look for fully automated in-line PUR perfect binders with the ability to handle larger page formats and thicker spines than those currently available.

With digital production driving nearly every aspect of binding and finishing today, it’s a good time to ask where your customers are headed and how you plan to track them. Now more than ever, binderies need to be looking to non-traditional suppliers, markets, and approaches to find the binding edge.

James Tressler is director of branch operations and Mid-Atlantic regional sales manager at C.P. Bourg, Inc., a leading technology developer and supplier of in-line and near-line document feeding, binding, and finishing equipment. His career in the binding industry spans nearly 20 years. C.P. Bourg can be found on the web at


  1. Bowker Reports U.S. Book Production Declines 3% in 2008, but ‘On Demand’ Publishing More than Doubles – (
  2. PIA Digital Printing Council “Marketing 4 Digital” Report on Book Publishing, 2007.
  3. See Case Study at