Paper 101.

This article presents a glossary of terms about papers. Acid-free papers are papers made without acid-forming components, which prevents internal chemical deterioration of the paper over time. In the U.S. each paper category has a specific basic sheet size associated with it. The basic size is used mainly to establish the paper's basis weight and does not necessarily indicate available sheet sizes. Outside of North America, the metric system is used to determine a paper's weight and size. The basis weight shows the weight of one ream (500 sheets) of basic size paper in pounds. The combination of the basic sheet size and basis weight determines whether a sheet is a 60-lb. text, 100-lb. cover, etc. A paper's brightness is defined by the percentage of light it reflects. Every white paper has its own brightness, which is measured on a bright meter machine, known in the U.S. as the GE scale. Other regions use a brightness scale based on the International Organization for Standardization. Papers are manufactured to either caliper or weight. Caliper refers to the thickness of a sheet of paper. In North America, it is frequently referred to in terms of points. The term finish refers to the surface of the paper, starting out with two basic choices--uncoated or coated.