Technical Articles

Saddle Stitching: There's More to It than Meets the Eye

Published in New England Printer & Publisher

by Frank Shear

Contrary to popular belief, saddle stitching isn't always easy to produce nor is it a commodity. The bad news is that there are many ways for problems to develop on "easy" saddle stitching projects. The good news is that there are ways to keep these problems at arm's length, "wow!" your customers and pad your bottom line.

The saddle stitching process isn't any more complicated than placing forms on top of other forms over a saddle and driving stitches through the gathered piece's backbone. Companion operations such as inline trimming, refolding and shrink wrapping increase the value of stitched products.

Many Product Choices

The world of saddle stitching is much broader than simply stitching forms and trimming them to 8œ" x 11". Automatically stitched and trimmed products can be as small as 3"x 6" and if trimmed offline, a lot smaller - final product sizes can be as small as 1"x 1œ". Foldouts, fold-ups, self-mailers, BRCs (business reply cards), BREs (envelopes), die cut forms, tabs, undersized and overhanging forms add pizzazz and real customer value. Special scoring and perforating techniques allow signatures with foldouts to remain together prior to the final trim-off. Some companies apply glue in trim-off margin areas, but typically this slows down production and increases costs.

For products that are smaller than standard machine minimums, run them multiple-up or bind them into larger size booklets. Either way, offline trimming is necessary to get them to their final size. Stitching heads can be positioned as little as 2 œ" apart. When laying out multiple-up small final sized jobs, make sure that the stitching heads don't come closer than three inches, center-to-center, or else two passes through the stitching machine will be necessary.

Would you like to mix and match many forms? Or, produce thick books? Find yourself a bindery with at least eight pockets plus a cover feeder for maximum design flexibility.

Job Planning

When executing projects with unfamiliar layouts, involve your saddle stitching expert early in the job planning stage. Simple changes can make huge differences. Many times your least expensive printing and prepress layout will end up costing you more because of downstream bindery inefficiency. Some machines offer a lot of leeway for head, face and foot trims. Inline trimmed books with 1Œ" face, 2" head and 2" foot trims are possible on some equipment. Although large trim-off areas waste paper, they may still be your best choice - if they eliminate 1) offline trimming and 2) the wait for special making-order paper sizes.

While there are very few saddle stitching absolutes, most stitching machines can run one-up pieces as small as 3"x 6", as large as 12"x 17" and as thick as Œ". One-up products smaller than 3"x 6" need to be trimmed offline. For jobs with bind-ins, check with your bindery for overhang limits. Although many saddle stitching machines' feeding sections and carrier chains can bind panels as short as 2", not all can.

Stitching pre-personalized work requires your stitching partner to maintain jobs in proper sort sequence. Maintaining order requires some unusual manufacturing and staging procedural steps. Since component staging, pocket loading, product packing and quality assurance are all essential in handling pre-personalized material, develop a solid relationship with a bindery with experience in doing this type of work.

Holding Forms With Foldouts Together During Saddle Stitching

If your job has a foldout (accordions, gate or multiple roll folds), every form in the job must have a consistent trim of at least 3/8" on the "jog-to" edge. Forms with foldouts frequently need to be temporarily held together in the trim-off margin area by either glue or special perforating techniques. Temporarily applied glue or perforations will be removed during the final trim. The glue application process requires constant monitoring and frequent sample pulls to ensure accurate glue placement and adhesion. In addition, if glue spreads too far into a piece, it won't be removed during the final trimming process. Because of these problems with glue, some binderies prefer to use special perforating processes as an inexpensive fastening alternative.

Protective Coatings On The Cover

If your job marks or scuffs during production, usually it's because the top of one signature rubs against the bottom of another during pocket feeding. Consider applying a coating such as film lamination or UV Coating when you have concerns about scratching or transit marking. If your cover has significant amounts of metallic or reflex blue ink, or has dark ink on one outside cover and white stock on the other, consider applying a paper coating. If you choose lamination, have your bindery use scratch-resistant laminate made from polyester, not polypropylene. (If a scuffing problem occurs on inside forms during production, your bindery should try loading pockets with lighter loads.)

Other Technical Tips

Avoid having a single sheet or a thin signature sticking out of either the head or foot because it will be crushed when joggers position the product for final head and foot trims.
For jobs with really light or porous stock, such as onionskin, expect slow production rates because slower machine cycle speeds are needed to avoid pulling doubles.
All saddle stitching machine in-feeder tables are not created equal. Those with pull pawls offer better book delivery into the trimming section on some jobs, which improves registration into the stops - giving more consistent trims. In addition, good in-feeder sections won't collapse or crush the laps (lips) of thin stock.
Reverse laps on a job will cause slow production rates. Try to keep all of your folios the same size and heading in the same direction. Your jogging-end trim margins should be consistently sized and your "off-end" trim margins should be sized within 1/8" of each other because poor production rates may result if they are not.
When stitching jobs with no lips (suction opening), either the head or foot must be closed so suction applied to the outside page of a signature will open to the center every time. If properly designed, even a 64-page signature can be opened this way.
On thick books, a little tear in the rounded section of the backbone is normal. Since the spine edge isn't fully supported during trimming, knives cut through the supported top pages but not completely through the bottom pages causing a small rip at the backbone. Since the laws of physics are at work here, there is no practical way to eliminate this minor problem.
When working with a die cut form, carefully plan your job so that no edges catch on the machinery during production.
Static can cause problems. Be careful in winter and dry atmospheric conditions.
Unbalanced signatures may require special handling to keep them from falling off the saddle or the chain. Experienced saddle stitching professionals usually can compensate for this problem with special machine rigs.

The world of saddle stitching is beautiful and varied. Hop in the saddle, ride the big horse and delight your customers by adding to the value you provide. There's more to this timeless binding method than meets the eye.

Frank Shear is President of Seaboard Bindery, a service-oriented trade bindery located in Woburn, Massachusetts. His company specializes in offering high quality perfect, PUR and layflat adhesive binding, saddle stitching, Wire-O™, plastic coil, laminating and other bindery solutions. Call Frank at (781) 932-3908.