Tell a Perfect Binder Operator that he needs to bind a project containing two page forms or synthetic flysheets and he is likely to run for the hills, babbling incoherently. If your perfect binding project design requires the use of either two page forms or synthetic fly sheets, here are a few tips to help the project go smoothly, while allowing Perfect Binder Operators to maintain their sanity.

A two page form of any material is less stable and more difficult to feed and collate, on nearly any stock weight. Stock type and basis weight can exacerbate this challenge. A 50# basis weight text is the minimum that should be considered when a two page form must be planned when using offset or coated stocks. Below a 50# basis weight, the mechanical calipers on the collator, designed to detect a mis-feed or double feed, simply will not work. Mechanical calipers are not sensitive enough to detect a form this thin. Two page forms on stock weights less than 50# basis weight could be missed during the feeding process and not discovered. This results in missing pages in the final product. If you must include a two page form(s) in your perfect bound project, consider increasing the basis weight of the stock to at least 60#. The additional paper cost will go a long way toward avoiding the production of a book with missing pages. An alternative planning option is to combine the two page form with other signature page count options. For example, combine the two-page and a four page into a six page signature. Or, redesign a two page and an eight page form to create six page and four page signatures. Allied Bindery can help you get creative in your planning approach, while helping to minimize potential production and quality problems.

Synthetic stocks, often used for flysheets, create additional challenges. A basis weight of 30# will not only be too thin to detect through the pocket feeder calipers, but the stock itself will have a tendency to curl into a cylinder shape. The curling of thin, synthetic stock generally takes place immediately after the flat cutting process. Curled stock simply will not feed through a collator pocket. The curling sequence can take place so rapidly that the synthetic sheet will often curl between the collator pocket and the binder. When this phenomenon occurs, the sheet will likely be bound crookedly into the spine of the book. Allied Bindery recommends synthetic stocks with a minimum basis weight of 32# to minimize the potential for curling.

A common question asked of Allied Bindery is whether or not the spine area of a perfect bound book needs to be “knocked out”. For non-printers, this question revolves around whether a coating (varnish, aqueous, ink or UV) can be applied to the spine area of the book cover, without negatively impacting adhesion.

If the spine area of a book cover must be knocked out, the printer must cut away a portion of the printing blanket. This cut away portion will then prevent coating from being applied to the press sheet. By not applying a coating to the spine area of the book cover, the adhesive will do a better job of adhering text pages to the cover. However, the printer will be unable to use the printing blanket again, because it was customized for a specific job. This can be expensive and time consuming for the printer.

There are a couple of things to be considered when determining whether or not a “knock out” of the spine is required. When a book is to be bound with EVA adhesive, the spine area should be knocked out to achieve best results. Although EVA adhesives are a fine choice for many text sheets, they are not formulated to stick well to varnishes, aqueous coatings, heavy ink coverage, or UV Coatings that are often applied to book covers. Knocking out the spine and hinge score areas will result in the best overall adhesion.

Choosing PUR adhesive will help overcome several of the performance shortfalls of EVA adhesive. PUR will stick very well to varnish coatings, aqueous coatings and nearly all ink choices (metallic being an exception). If the printer is utilizing a UV coating on a book cover or the spine area of text sheets, it is still a good idea to knock out these areas. Although PUR may stick to a UV coating, the effectiveness of the adhesion is determined by the amount of silicone content and the resulting Dyne level of the coating. Since the silicone level in a UV coating is not controlled by the bindery, the risk of the PUR not sticking to UV coating is reasonably high. As a result, Allied Bindery recommends knocking out the spine and hinge score areas of a book cover when a UV coating is being used.

We encourage you to contact your Allied Bindery Representative to discuss project planning issues such as cover knock outs and coatings. Our experience and ideas will likely save you money or help avoid the creation of a production problem.

Your customer has just requested a perfect bound book with enhanced capabilities to lie flat when opened.  You check your list of trade
bindery service providers and see that some of them promote the ability to
produce Layflat Binding (or Stayflat or Otabind).  Problem solved, right?

Not necessarily.  There are several critical planning steps that must be considered during the design and prepress stages of the project that ultimately determine the cosmetic and functional success or failure of the book.

A successful Layflat binding style is accomplished by building the book so that the spine of the book block is not attached to the spine of the book cover as with a standard perfect bound product.  The Layflat book block must first be adhered to a fabric liner rather than a book cover.  The bound book block will then be attached to the cover between a pair of hinge scores specifically placed on the front and back cover.  This design allows the spine
of the book cover to separate from the book block when the book is opened,
allowing the spine of the book block to float above the book cover.  This design reduces resistance and allows for an enhanced Layflat characteristic when the book is opened.

In order to build a successful Layflat product, design and prepress planning must incorporate specific requirements for hinge scores, graphics and text placement on the covers and interior text pages.  Design requirements must also provide consideration for cross alignments, page borders, and if necessary, drill hole placement.  Failure to plan for these critical characteristics will result in an unhappy customer.

The Sales and Planning Professionals at Allied Bindery are prepared to assist you with the critical planning requirements for Layflat Binding.
Give us a call and let us show you how we can help ensure a successful
project for you.