Special Paper for Printing Method

The more you know about the characteristics of paper, the better able you will be to save money when specifying paper for the printing jobs. In fact , in the event that you specify the qualities you require in your paper, rather than specific name brand, your printer may be able to offer a few acceptable options.

Each paper stock possesses the following characteristics: surface texture, brightness, color, whiteness (if you specify a white sheet), opacity, grain direction, weight, bulk, caliper, and size.

Uncoated and coated paper have different surface textures. In the papermaking process, uncoated stock has been compressed between metal rollers (calendared) only to a limited degree, yielding vellum, antique, wove, and smooth surfaces (from rough to smooth, depending on the number of calendaring). Coated paper varies from roughest (matte) to smoother (dull) to smoothest (gloss), also depending on the number of calendaring. Papermaking machines can even impress such textures as "linen" and "canvas" written down. The smoother the paper, the better the "holdout" (the better the ink sits up on the top of paper in place of being absorbed into the fibers).

Opacity determines show-through. A sheet with high opacity will prevent solids, screens, and halftones from being visible through the opposite side of the sheet, which could otherwise be quite distracting. Colored sheets are usually more opaque than white sheets. This quality is rated on a 1 to 100 scale. Most sheets fall in the 80 to high 90 range.
Weight is based on the size of 500 sheets (a ream) of paper. A ream of 80# cover, measured at 20" x 26", weighs 80 pounds. The same paper in text weight still weighs 80 pounds but the sheet size is different: 25" x 38". It is therefore a thinner sheet. Of course these sheets can be cut to an inferior size. This is just a convention for precisely describing different grades of paper, such as bond, offset, etc . Another scale is in points (thousandths of an inch). You might, for instance, specify a cover for a perfect-bound book as a 10 pt. sheet. To be safe, always ask for samples.
Caliper is the thickness of paper when measured with a micrometer. It is related to bulk, which is a relative way of measuring the thickness as related to the basis weight of a sheet. For instance, 75# Hi-Bulk is thick enough to pass US Postal regulations for reply card thickness (7 pt. ). Another sheet of this weight might have been further calendared and its fibers compressed more, yielding a thinner sheet. Lower bulk reduces opacity. Higher bulk will increase the overall thickness of a book. Therefore , it helps to know a paper's measure in pages per inch (caliper).

All of these qualities affect the runnability and printability of the paper, as well as its appearance, so listen to your printer's advice. However , please request samples, both printed and unprinted, of any sheet suggested by your printer. Only by actually seeing a printed sheet can you know whether a particular paper will work for your own job.