If you’ve ever visited a printing plant you may have thought that the contraptions in the bindery section resembled a Rube Goldberg fantasy. Binding machines have evolved over the years from straight stitching functions to providing tools that save money, increase flexibility, and improve response.
Despite such innovations, however, the two basic methods of binding remain the same: saddle-stitching and perfect binding.
Binding by saddle-stitching
Saddle-stitching involves stapling the spine of a folded catalog to keep the pages together. The process starts at the feeder pockets, which hold the forms, or press signatures. The forms, packaged in 5-ft.- or 8-ft.-long stacks strapped into logs, are delivered from the pressroom to the bindery on pallets by forklift.
After a bindery employee prepares the forms spine down and face forward for the pocket feeder, the bindery pocket equipment pulls the forms one at a time out of the stack. The machine opens the form with a series of vacuum suction devices and “shoes” or “fingers” drop the open form onto the bindery line. The bindery controller tells the pocket when to “fire,” or feed another form. As each pocket fires, another form drops on the bindery line. A simple catalog would have the order form, assuming it was the innermost form, drop first; the next pocket would feed the body forms, and the last pocket would drop the cover.
Most bindery lines have a gathering chain with pins that separate each catalog by forcing the book to collect at, or jog to, the bottom of the form. As the catalog travels down the line, the bindery collates the components, pushing the book against the pins.
Automatic staplers fed from spools of wire then stitch the book by stapling the spine. The address is ink-jetted onto the order form and the back cover, and the head, the foot, and the face (or the top, the bottom, and the side) of the catalog are cropped to the final trim size.
Forms supplied to the bindery must meet certain standards. For the pocket feeder to be able to open the form and drop it onto the bindery line, the pages on one side of the center spread must be larger than the pages on the other. This forms a lap (also called a lip) so that the machine’s finger can open the form. The pages before the center of the form are called low folio, meaning the page numbers are the smaller than those of the high-folio pages following the center.
The ink-jet addressing location determines the pickup lap location. Most catalogs have the postal address ink-jetted on the back cover, in which case the pickup lap is on the low-folio side of the book. Bindery specifications require a 3/8-in. minimum bindery lap, though forms supplied internally from the printer usually have a 1/4-in. lap to save paper. The printer can also cheat the lap or deliver a form with alternating 1/4-in. and 3/8-in. laps. This still gives the finger the necessary pickup lap but wastes less paper. When providing forms from outside vendors to a bindery, however, stick with the 3/8-in. bindery lap to avoid potential bindery slowdown charges.
As for the order forms and bind-ins that are not full height, remember that you still need to compensate for the foot trim, since the catalogs jog to the bottom. Therefore, the print safety area of 1/4 in. on the bottom of the piece needs to be extended to 3/8 in.
Limitations to saddle-stitching
The overriding constraint of the saddle-stitching bindery process is how slow it is compared with the printing process. A gravure press or a high-speed offset press can deliver product much faster than a bindery can stitch it. While most bindery machines are said to handle 16,000-20,000 books an hour, the bindery is slowed by each complication to the process.
For example, a bindery may be able to run a simple book with ink-jetting on the back cover full-out at 16,000 books an hour, but when you add ink-jetting to the inside order form, the speed may drop to 14,000 catalogs an hour. Adding forms and functions such as demographic binding, dot-whacking, and bind-ins slows the process significantly.
The number of bindery pockets available can be another limitation. Most machines have a 20-pocket limit, though some magazine plants have 36-pocket machines. While many mailers cannot fathom using 20 pockets now, it could become a greater concern as binding becomes further sophisticated.
For instance, more mailers may cobind and comail books for postal discounts, test different offers, and target specific customers, which may require more pockets on the bindery line. Particularly before the fall mailing season, the demand for 36-pocket machines among customers could result in long lead times, pushing out the creative and merchandising efforts to earlier dates.
Some saddle-stitched catalogs have to contend with shingling — when the thickness of the book causes the outside forms to fall short of the face when the book is closed. But shingling is a typically a concern for books with more than 120 pages. The printer can compensate for this by making each outside form slightly longer, with the artwork floated uniformly to the face with a larger gutter.
A larger drawback of saddle-stitching is the overall cost. With demographic-bind run rates, multiple ink-jet heads, and increased pockets, bindery costs can get steep fast, easily outstripping any benefit of target marketing and increasing response rates. The cost to demographically bind a catalog can reach $5/M; the marketing lift from the versioning needs to cover the increased cost.
Catalogers tend to overlook perfect, or square-back, binding because they are unfamiliar with the technical requirements or appropriate uses. Perfect-bound catalogs, which have a “spine” as books do, have long shelf lives and are more durable than their saddle-stitched cousins. That’s why they tend to be a good choice for larger catalogs or books that double as a reference source, such as hardware, seed, and technical-product catalogs.
To use perfect binding, you must consider the thickness of your catalog. Catalogs should have more than 80 pages for perfect binding, because the spine must be at least 1/8 in. thick. Spines can go as large as 2 in. thick, depending on supplier capabilities.
Like saddle-stitching, perfect binding starts at the feeder pockets that hold the signatures. The signatures and the inserts are pulled onto a machine’s raceway one on top of the next. The forms are pushed along forcing the components to jog to the head or the foot, depending on the orientation. You should keep smaller signatures (such as four-page and eight-page forms) toward the middle of the book whenever possible, with 16-page or larger signatures on the outside.
Once all of the inserts are collated, a clamp grasps the pages at the spine and carries them to the spine preparation area. Here, the spine is ground off smooth, then a roughing router marks the spine to allow for maximum contact with the adhesive. Allow for a 1/8-in. spine trim-off in your design — or more, if you have thick paper or a high page count — and use the appropriate trims on inserts such as reply cards and order forms.
Hot-melt glue is applied to the entire spine and about 1/16 in. up the front and the back. As the catalog body pages go through the gluing stations, the covers are fed into the binder where they are scored and wrapped around the body. On the backside of the front cover, your designers must block out ink, varnish, or other coatings on the spine and an additional 1/4 in. off the spine on the inside front and back cover. This will allow the body pages to adhere properly to the spine.
After leaving the gluing stations, the catalog will travel to the knife section of the bindery line, where the open edges will be trimmed off for a clean, finished appearance. Allow for a minimum of 1/8 in. of space at the head, the foot, and the face for trimming. Many machines have a maximum trim as well, so always check with your bindery before producing your printed forms.
Though deciding how to bind your catalog is largely a question of book size, here are two more points to remember. Because the covers are fed in just prior to gluing to the body pages, perfect binding enables less control over the variation in covers compared to saddle-stitching.
And unlike with saddle-stitching, perfect-bound body pages are collated first, and the cover is applied toward the end of the process. So covers should be produced on a heavier paper stock than the body pages (at least 60 lb.), as lighter stocks can cause wrinkling on the spine.
Tim Gable is director of print production for Madison, VA-based mailer Plow & Hearth; Matt Wrhel is production director/Web marketing manager for Gardens Alive, a Lawrenceburg, IN-based cataloger.
The Lowdown on Demographic Binding
Modern direct marketing came of age with the advent of the demographic bind — the ability to create different versions of a catalog. This allows the marketer to craft multiple offers to its customers and test their effectiveness. For instance, to reactivate buyers who have not purchased from you in three years, you may prepare a special cover version with a banner that says “Save 10% on this order!” and mail it only to the dormant list.
Using the demographic bind requires you to prepare your address tapes as two book versions within one mail stream. You would print two cover versions to the quantity needed for each version, allowing for a slight spoilage increase because the quantity is split. The body pages would be common to both versions, so the print order would be for the complete circulation.
The bindery line would be set up with the two cover versions in two separate bindery feeder pockets. As a reactivation customer’s name was read from the bindery tapes and sent to the bindery line, the correct feeder pocket with the “Save 10%” cover would fire instead of the regular cover. If the next name were a “regular” customer, the regular cover would feed onto the gathering chain. Because the different names were on the same mail stream tape, you would get the lower postal rates of the combined circulation rather than the higher postage rates of two smaller circulations.
Many mailers use demographic binding to include special pages or a bind-in to only a portion of the customer list. For example, if you had a limited-quantity offer that you wanted only your best customers to see, you would have your service bureau segment out those customers so that you could select this list as a different book version within the same mailing stream. As with the reactivation customers, when the tape read the best-customer’s name and sent it to the bindery line to create the catalog, the feeder pocket with the bind-in would also fire and feed a bind-in onto the gathering chain.
Some other demographic customizations enable you to have a body version with different phone numbers, different prices, or even different products. The only constraints on bindery versions are the number of feeder pockets available on a bindery machine, the amount of bindery time available, and the amount of money you want to spend.