Quick - what parts of a case-bound book are critical to its overall strength and longevity? While the sewn spine binds the signatures, the endsheets are actually the key stress points in a case-bound book. For that reason, endsheets must be carefully considered and produced to be sure your books possess the highest strength and durability.
Endsheets for case-bound books are typically four-page forms tipped to the first and last signatures of the book block. A one-eighth-inch line of glue along the spine adheres the endsheet to the book block. They are then glued to the insides of the covers to marry the case to the book block.
In order to perform their function properly, endsheet stock should be stronger than that of the book block. At Eckhart and Company, we recommend uncoated stock of at least 80 lb. text weight for maximum strength and adhesion. Keep in mind that the weight of the endsheet stock should increase as the size and weight of the book increases. In addition, endsheets should be the same size as untrimmed signatures to facilitate the binding process.
Prepare printed endsheets carefully: While printed endsheets are popular for many applications, inks and coatings will reduce strength and longevity. Use a C1S (coating on one side only) stock for endsheets if you want the printed side to be coated.
Keep Paper Grain Parallel: Paper grain direction, an important consideration for all book binding products, must be parallel to the spine on endsheets. This will give you a cleaner fold and a stronger endsheet. Also, endsheets accept or release moisture after books are bound, and incorrect paper grain will cause the endsheets to expand head to foot. This will compromise cover quality as conflicting endsheet and board grains work against each other, resulting in warped covers and wrinkled endsheets.
The Eckhart Advantage
At Eckhart & Company, our complete Smyth-sewing and case-making services make us your single resource for high-quality, durable case binding production. Looking for design flexibility? We can also perform case binding on perfect-bound and Wire-O-bound book blocks. Call Eckhart and Company today to plan your next successful post press project!