Perfect binding is a process in which signatures of pages are bound together using adhesives to create a professional-looking product. It involves stacking signatures, applying glue at the edges, and wrapping the cover around the book, which is later trimmed to size. Methods of perfect binding include the traditional EVA glue, layflat binding, and PUR binding.
Layflat binding is an antiquated form of softcover binding in which the cover is glued to the sides of the spine and gauze is placed on the edge to hold signatures together, resulting in a book that can literally lay flat while opened. Over twenty years ago, it was a popular bookbinding method used for high page count manuals and catalogs that would require the user to have a section open for hours at a time. However, the ongoing improvement of hot melt adhesives and a comparably steep price tag have rendered layflat binding obsolete; one would be hard-pressed to find a supplier who offers this capability.
While polyurethane reactive, or PUR, was developed in the 1930s, it wasn’t until more recent years that it started being used in adhesives for manufacturing. It refers to a softcover bookbinding method in which the pages and cover are glued together at the spine. The key advantages of PUR binding are:
- PUR is an alternative and cost-effective option to layflat binding
- It is more durable than standard adhesives such as EVA glue
- It can adhere to the widest variety of substrates
- Environmentally friendly with low VOCs
- Quick-drying and curing which means quicker turnaround times