Published Article

Proper Planning Leads to Perfect Binding Success By: Fred Daubert, Vice President, The Riverside Group
Published in: Printing News

It may seem like an old-fashioned process, but modern perfect binding production is pretty advanced. The latest binding equipment allows more books to be bound in a shorter amount of time, and with less make-ready waste than ever before. In the hands of an experienced binder, these machines also allow for a wide range of cover design and adhesive options, making perfect binding suitable for a variety of book applications.

With this many options available, it's more important than ever to plan perfect binding projects carefully. That includes plenty of communication with your binder, who may be able to make layout or design suggestions that save you time and money while providing higher overall quality.

Adhesive Options
Choosing the proper adhesive is critical for the overall success of your project. The main adhesive families are EVA (ethylene vinyl acetate) and polyurethane reactive (PUR); each has distinct characteristics that are suitable for a wide range of applications.

Standard perfect binding is performed with an EVA hot-melt adhesive, which is applied to the spine of the book during binding. EVA adhesives set in minutes, allowing books to be handled immediately after binding. There are dozens of different EVA adhesive formulas for use on a wide range of projects. A high-quality finisher will be able find one that offers great results on even the toughest jobs.

In order for the adhesive to hold the book together, the spine must be ground down to expose raw paper fiber. The strength of the bind is directly proportional to the amount of paper fiber exposed. For most applications, a 1/8" grind-off margin at the spine should yield sufficient results, although this may vary by bindery. Heavy ink or coating coverage in the spine will compromise adhesion and may require additional grinding to expose sufficient paper fiber.

PUR is a cross-linked adhesive that seeps deep into paper fibers to provide a bind that's three times as strong as standard EVA perfect binding. The chemistry of PUR adhesive makes it suitable for applications that EVA perfect binding may have trouble adhering to sufficiently, such as those with high-gloss finishes or full-color ink inside the cover. Its flexibility makes it ideal for heavy-use, long-life applications such as paper swatch books. Perhaps the only limitation of PUR binding is its drying time; up to 24 hours are needed for PUR-bound books to fully cure.

Layout Considerations
It's important to involve your bindery during the design process to be sure layouts are optimized for efficient production and best appearance. Here are a few things to keep in mind:

Cover options - There are several cover styles and options available for perfect bound books. Four-page and eight-page gatefolds; foldout panels and removable cards; pocket covers and die cut windows are just a few of these options. Foldout covers can be designed flush with the text or undersized. Keep in mind that books with flush covers require two passes through the binder. The first pass involves trimming the book block on three sides and applying the glue; the second pass attaches the cover and trims the book at the head and foot.

Crossovers - Crossovers should appear to meet right at the spine. To achieve this effect, stop images 1/16" short of the 1/8" grind-off area. The thickness of your book may require this margin to be nudged higher or lower. Let your bindery help you plan crossovers for optimum appearance.

Trim margins - Leave at least 1/8" trim margin at the face, head and foot. These margins should be same for all forms. On the cover, leave an extra 1/8" margin at the head and foot for a glue trap. This extra margin keeps glue from seeping on to subsequent books during binding. Also, make sure the paper grain direction is parallel to the spine of the book. Books printed cross-grain have a higher chance of cracking and splitting at the spine, compromising the strength of the bind and the longevity of the book.

Keep in mind that these margins are meant to be guidelines, not absolutes. It's common for projects to require margins that fall outside of these parameters. A knowledgeable bindery may be able to suggest alternative designs for projects with complex or unusual layout requirements.

Technical Tips Here are a few planning, design and production tips to keep in mind:

Whenever possible, keep inks, varnishes and coatings away from the spine - As we discussed earlier, these all compromise the adhesion of a perfect bound book. If the presence of these elements is unavoidable, PUR binding will offer the strongest bind possible.

Ask about multiple-up layouts - A two- or three-up layout allows for reduced turnaround times on certain projects. However, not all binderies can handle multiple-up layouts efficiently. Check with your post press services provider about the possibility of multiple-up layouts, but keep in mind that these layouts must be approved by your bindery.

Choose a bindery that with several milling options - Both perfect binding and PUR binding processes require spines to be roughened prior to glue application to ensure proper adhesion. This is performed with a milling wheel that grinds the paper to expose paper fiber. The aggressiveness of the grind depends on the amount of paper available at the spine; the presence of inks and coatings; paper chemistry and other factors. A bindery with several milling options will be able to determine which one offers the strongest possible bind without compromising appearance of production efficiency.

Communicate packaging needs - You should specify how your books will be handled once they leave the bindery. This will help your binder suggest packaging options that are appropriate for your application. For example, if books will be sent to a central location for further distribution, shrink-wrapped skids may be preferable to boxes, which take longer to package.

The design of your books may also impact how they're packaged. Certain covers may scuff easily during transit, so consider coating or film laminating as a protective measure. If the books are already printed, shrink wrapping or slip sheeting may be necessary to avoid scuffing or marking. Important note: shrink wrapping should not be performed on PUR-bound books within 24 hours of binding. PUR adhesive requires 24 hours to fully cure, and moisture actually helps this process. Shrink wrapping keeps moisture out, so make sure books have cured first.

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Modern perfect binding production has the flexibility to allow for a wide range of design and layout possibilities. Coupled with the latest equipment and a knowledgeable bindery, well-designed books can be produced efficiently with beautiful results. The key is to involve your bindery during the planning of these projects to be sure you're aware of all possibilities.

Fred Daubert is Vice President of the Riverside Group, an "under-one-roof" bookbinding and finishing company located in Rochester, N.Y. They specialize in both soft and hard cover binding production, including perfect binding; PUR binding; notch binding; Smyth sewing; cased-in mechanical and perfect binding; and more. Additional capabilities include mechanical binding; laminating and UV coating; folding; gluing; tabbing; die cutting; foil stamping; embossing and more. For more information, contact Fred Daubert at (800)777-2463, or book@riversidegroup.com.