Perfect Bound Books: Exploring the Perfect Binding Process

estimated reading time: 5 minutes

The Binding Process of Perfect Bound Books

Perfect Binding is one of the most widely used book binding methods. Its professional appearance and affordability make it a popular choice for softcover books, including novels, catalogs, magazines, and other bound documents that have medium to high page counts.

Unlike saddle stitching or "punch and bind" styles like spiral coil, wire-o, and comb binding, the perfect binding method results in a flat, printable spine. Perfect bound books also have clean and arrow straight edges which provide a very uniform and high quality look.

Long considered a low cost alternative to hardcover binding, perfect bound books are made with a wraparound cardstock cover and a strong adhesive to keep the pages intact. These features give perfect bound books the durability to stand up to frequent use.

Now without further ado, let's explore the steps in the perfect binding process to give you a clearer understanding of how these books are made.

Preparing the Cover

The pages of a perfect bound book are printed on text weight paper but the cover is almost always printed on heavier cardstock to add structure and durability. In most cases, the cover is also given a protective clear coat such as a UV coating, aqueous coating or laminate. In addition, the cover is initially cut to a size that is slightly taller than the height desired for the finished book. This is done to create a "glue trap" to collect any extra adhesive that might seep out near the end of the spine as the cover is wrapped over the pages during assembly. This extra cover material will be removed during the final trim of the book.

Creating the Page Block

Once the page sheets have been printed, they are gathered together in the correct order. This collated stack of pages is known as the page block. It is also sometimes referred to as the book block or text block. Automated collating equipment is often used to efficiently sort the pages into the proper order and align them into a crisp and compact stack.

Roughing up the Binding Edge

The spine is the anchor point for the book's pages and cover, so it is essential these components are securely fastened together. In fact, one of the most crucial steps in the perfect binding process is to prepare the spine of the book so the adhesive can make a strong bond. So, after the pages have been assembled in order, the edge of the page block must be notched or roughened using rotating blades, abrasives, or some other means. Roughing up the spinal edge of the page block exposes more paper fibers, thus providing additional surface area for the adhesive to penetrate and form a bond.

Applying the Adhesive

The next step in the perfect binding process is to apply the adhesive to the spine. Perfect binding uses a hot-melt adhesive, which offers a strong and durable bond yet is flexible enough to withstand frequent use. Since it is important that the adhesive be applied in a thin and even layer along the entire length of the spine, a machine is used to ensure the glue is distributed in a precise and consistent manner. By the way, the importance of a strong bond is why the perfect binding method is not recommended for books thinner than .125" (1/8"). This is because the adhesive needs a bonding surface of at least .125" wide to ensure strong adhesion.

Affixing the Cover

Once the adhesive has been applied over the spinal edge of the page block, the page block will be aligned with, and affixed to, the center of the inside cover. Just prior to the page block being set in place, a shallow channel will have been formed in the center of the book's cover so it can accept the page block. This channel will have been made using two 90 degree folds, which will form the right-angle bends on either side of the book's spine. A hinge score will also have been added to the front cover and the back cover near the spine. These hinge scores will allow the books to open with relative ease while putting less pressure on the spine. Finally, once the page block and cover have been joined together at the spine, the book's front and back covers are pressed tightly against the page block. Because perfect bound books use a one-piece wraparound cover, its transition from the front cover to the spine, and the spine to the back cover, is seamless and smooth.

Cooling and Setting

The assembling phase of the book is pretty much complete at this point, but the hot glue needs to cool so it can set. How long this takes will depend on the type of adhesive used. For example, Ethylene Vinyl Acetate (EVA) bookbinding glue will reach full cure very quickly. Polyurethane Reactive glue (PUR) will take longer to reach full cure, but it will result in a stronger and more flexible bond (greater strength and flexibility is why PUR is the preferred adhesive for perfect binding).

Trimming the Open Edges

Once the books are able to be handled, they are trimmed to the exact dimensions specified for the project. Strong cutting blades are used to remove the excess paper from the three open edges of the book (head, foot, and face). Several books can even be trimmed at one time if their combined thickness will fit within the cutting mechanism. Once the trimming step is complete, the books are ready for distribution.

Needless to say, the perfect binding process involves a series of detailed steps. These steps transform individual pages and a wraparound cover into a high-quality book with a flat spine and straight "perfect" edges, hence the name "Perfect Binding."

Did you know Color Vision specializes in Custom Book Printing?

Since 1984, custom book printing has been one of Color Vision's specialties. So whether you have a need for perfect bound books or any other types of books, we are your one-stop source for professional printing and binding at affordable rates.

Just give us a call at 800-543-6299 when you're ready to discuss your project. Or, if you have your specs handy and want to receive a quotation by email, simply fill out our easy Quote Request form.

By the way, Color Vision uses PUR adhesive on all perfect bound book projects. Even though PUR is far superior to EVA glue, we offer it at no additional charge.

As always, we hope to hear from you soon and look forward to assisting with your custom printing and binding needs!