Judging a Book by Its Binding
With the steady adoption of all sorts of digital printing systems, more printers—and non-printers—are now producing soft- and hard-cover books. There are loads of adhesive binder models out there, from tabletop models to “big iron” machines that take up lots of floor space.
Many small- and medium-size digital print shops will purchase a perfect binder and assume they’re good to go with a quality product. While such shops are now capable of producing a bound book, many of them don’t know the standards by which soft-cover, adhesive-bound books are measured.
Yes, that’s right, binding standards. The two tests most commonly used are the page-pull and flex tests.
- The page-pull test measures the strength of the page binding perpendicular to the spine. A testing machine (typically a Moffett unit) literally pulls a page out of the binding using a hydraulic system. The amount of force required is measured on a gauge; the minimum standard for this test is 30 lbs. of force. If it takes higher values to pull out pages, that’s a good thing. Pull testing is conducted on pages in the middle and at both ends of the book.
- The second widely used test is the flex test. This involves another testing machine that “flexes” the page back and forth at 50 cycles per minute, with two pounds of force pulling on the page. A baseline standard for this test is 500 flexes without failure. Some printers set much higher standards. Yearbook printers, and other “memory product” printers, may require the binding to withstand 1,000 flexes, for example.
Printing Industry of America has an excellent video showing the complete testing process:
It’s critical to know the bind quality of the book you’re producing, and that it’s up to par. You don’t have to test every book, but pulling one sample from a run and testing it is a good idea.