Derived from cellulose (plant) fibers that are made into pulp and felted (pressed) together, paper is one of the most common of man-made materials. There are approximately 7,000 types of paper, used not for writing or printing, but for products like paper bags and cardboard boxes.

The oldest extant writing surfaces include Babylonian clay tablets and Indian palm leaves. Around 3000 b.c., the Egyptians developed a writing material using papyrus, the plant for which paper is named. This substance was composed of strips cut from stalks of the papyrus reed, which were dried, laid across each other crosswise, and glued together to form a somewhat nubby writing surface. Other early materials were parchment, made from the untanned skins of sheep or goats and vellum, or fine parchment, made from calf-, kid-, and lambskin. Used in Europe from the second century b.c., they were expensive and impractical--the equivalent of...