What’s the deal about “paper” in a book?

Paper choice always matters in a print job.

For one thing, it can represent a significant portion of the cost of an average print job. For another, paper has to suit your purpose. Is the paper weight appropriate? Will ink show through to the other side? Will it be OK going through the mail? Paper also affects the design, so you need to choose carefully.
Fortunately, here at Print-Tech we’re paper experts, and we’re happy to help customers specify the right paper. Some fundamental paper knowledge will help, so in this issue, we’ll cover some paper basics.

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Major Paper Categories
 
Printing papers fall into these general categories, or grades: bond, offset, text, coated, and cover. Most of the time, you’ll use one of these papers for your print jobs. Less common categories are newsprint, tag, lightweight (or Bible), Bristol and index. Each paper category serves a particular purpose. It’s our job to help you select the right sheet.
Basis Weights
 
“Basis weight” is a key term in commercial printing. Every grade of paper is made in one basic size, which is used to determine its basis weight. Printing papers in the U.S. are identified by their basis weight – the weight in pounds of a ream of paper (500 sheets) in the basic size. Papers can have different basic sizes. For book papers, it’s 25″ x 28″. For cover papers, it’s 20″ x 26″. A ream of each can weigh 80 pounds, even though they have different basic sizes. This is why an 80 pound cover is heavier than a 100 pound text sheet, and why these weights can become confusing. Paper weight is usually indicated by using the “#” symbol. For example, “20#” means “20 pounds per basis ream of 500 sheets.”
So we might spec an 80# offset sheet for a brochure, or an 80# cover sheet for a poster. Cover stock is thicker and bulkier than an offset sheet. A lightweight text sheet might be too thin, or flimsy, for a particular project. (A quick rule of thumb: the higher the basis weight, the heavier the stock. So a 100# cover is heavier than an 80# cover.)

 

Coated vs. Uncoated Paper
 

Coated paper is manufactured at the mill with a surface layer of coating, giving it a smooth finish, or sheen, that uncoated paper may not have. There are many kinds of coated paper. Dull-, silk-, or matte coated paper has a non-gloss finish. Gloss-coated paper is, as expected, shinier, and more polished. Different brands have different sheens for each type, and our salespeople can show you samples and help with the selection process.
Gloss-coated paper grabs attention and helps images “jump” off the page. Coated paper prevents the ink from absorbing into the paper. This allows for cleaner, crisper printing, especially in photos, solids, blends and fine details. It’s ideal for some projects (magazines, book covers, flyers, posters) but not for others (business cards, forms, book text).
Uncoated paper stock is paper that has not been coated with a surface sealant. Inks dry by absorbing into the paper like a sponge. This paper type can soften the colors that are printed. Uncoated papers comprise a vast number of paper types and are available in a variety of surfaces, both smooth and textured. If a printed piece will be written on (return form, reply postcard, survey), then uncoated stock is ideal, since ink could smear on coated paper.
This basic introduction to paper weights and finishes will benefit you when working with your printer. Over time, you’ll appreciate the difference between, say, a 70# offset and an 80# cover, and you’ll be able to identify a matte finish as opposed to a gloss finish.