Smyth sewn, adhesive bound, and mechanically bound book blocks can be cased-in with either round or square back. The “back” referencing the spine shape.
o Round Back: the spine will be mechanically rounded to shape the capped and trimmed paper and glue. The case will be made with a paper backliner to allow the cover to follow the curvature of the rounded book block spine.
o Square Back: the spine maintains its shape integrity with a hard board strip and the book block is not rounded. For thin books under 3/8” thickness or oblong books, this construction is vital to the book’s durability, and provides a more traditional look.