Perfect Bound Book Printing: The Importance of a Hinge Score

estimated reading time: 5 minutes

What is a Hinge Score in Perfect Binding?

A "Hinge Score" is a precise indentation, mechanically pressed into the cardstock cover of a perfect bound book during the manufacturing process.

Hinge scores are positioned a short distance from the book's spine. They are placed parallel to the spine and run the entire length of the cover. The purpose of hinge scores is to enhance the book's performance and extend its lifespan.

There will actually be two hinge scores on a perfect bound book - one on the front cover and one on the back cover. Hinge scores are added after the book's cover has been printed but before the cover is glued over the page block.

These scores provide a controlled flex point - or "hinge" - where the cover is meant to bend when the book is opened. Without a hinge score, the book's cover would bend right at the edge of the spine, increasing the likelihood of stress damage and premature wear.

Why the Cover Should Never Bend at the Spine Edge

Many people assume a perfect bound book's cover will bend directly at the spine when the book is opened. But in reality, allowing the book's cover to flex at the spine places unnecessary stress on the paper fibers, which can weaken the cover and shorten the life of the book.

By adding a hinge score, the cover's bending point is shifting slightly away from the spine. By positioning this controlled flex line alongside the spine rather than directly on it, the cover maintains its structural integrity.

Plus, because hinge scores are engineered specifically to flex, the book opens more smoothly and places far less strain on the cardstock cover and glued spine.

Design Considerations for a Hinge Score

Hinge scores are not printed on the book's cover artwork, nor are they part of the file setup. Hinge scoring is a finishing operation done by your book printer after the cover has been printed but before the book is bound.

Having said that, it is still important to be mindful of the hinge area when laying out the artwork for a perfect bound book. For example, many designers avoid placing important content, such as text or faces, in the hinge area of the front and back covers. This is because the hinge score may potentially distort some of the finer details.

Also, when a book is created with hinge scores, the binding glue will be extended around the edges of the spine a little bit. This allows the inside front cover to adhere to a small section of the book's first interior page and the inside back cover to adhere to a small section of the last interior page. These extra laps of glue provide stability to the hinge mechanism.

So it is recommended that important content not be placed near the hinge area of the covers, or near the hinge area of the first or last interior pages.

Why Hinge Scores are Especially Important for Laminated or UV-Coated Book Covers

Many perfect bound books are ordered with an optional laminate or UV coating applied to the cover. A laminate is a durable plastic film bonded to the cover using heat and pressure. A UV-coating is a polymer resin applied in liquid form and solidified into a tough film using Ultraviolet light. Both of these options add a layer of protection against moisture, tears, and scuffs.

Since these finishing options also add some rigidity to the book's cover, they do not tolerate sharp, unprepared folds. Hence, it is crucial that the book's cover contain properly placed hinge scores.

The hinge scores will pre-compress the paper fibers in a controlled way, allowing the cover to pivot smoothly along a defined channel without stressing the laminate or UV coating. Otherwise, forcing a laminated or UV-coated book cover to bend sharply at the spine would lead to visible fracture lines along the fold. Needless to say, this greatly diminishes the appearance and perceived quality of the book.

In short, when a book's cover is enhanced with a laminate or UV coating, a hinge score is a structural necessity. It safeguards the finish from stress cracking while allowing the cover to open smoothly and comfortably.

A Hinge Score is a Sign of Professional-Grade Book Construction

Maybe you weren't familiar with hinge scores until reading this article, but as you can see, they have a major impact on how a book feels, how it performs, and how long the cover lasts. It's one of those behind-the-scenes details that professional book printers automatically include - and that many people only learn about after they've experienced a problem.

A hinge score may seem like a small detail, but when creating perfect bound books, it is the small structural details that matter. By allowing the cover to flex independently from the glued spine, a properly placed hinge score reduces stress on the cover and spine. The result is a book that opens smoothly, stays new looking longer, and has a premium, professional feel.

Hinge scoring does require additional equipment, time, and knowledge in the finishing department. But it is one of those details that separate average perfect binding from professional perfect binding. While a low-budget or inexperienced print operation may omit hinge scoring to save production time, it's a step that experienced book printers automatically include because they understand how covers behave after binding and finishing.

Color Vision Specializes in Custom Book Printing

For over 40 years, Color Vision has focused on doing the little things that make a big difference in how our books look and perform. That's why every perfect bound book we produce includes hinge scores. This ensures your books will not only look professional, they'll hold up to real-world use.

So if you have an upcoming project and would like to receive a quote, simply fill out our easy Quote Request form and we will email a quote to you. Or, if you prefer to discuss your project by phone, just give us a call at 800-543-6299 and we'll be happy to help.

By the way, in addition to adding hinge scores, Color Vision also 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!