Paper - Hand-made Paper, Machine-made Paper, Paper Categories, Paper Weights

Paper was probably first produced from bamboo and rag fibers about 2,000 years ago. By the eighth century, papermaking technology had spread to the Middle East. By the middle of the twelfth century, the Moors had transplanted the technology to Spain, from where it spread throughout Europe. Rags continued to be the chief source of paper fibers until the introduction of papermaking machinery in the early 1800s, when it became possible to obtain papermaking fibers from wood.

Hand-made and machine-made papers both consist of tiny cellulosic fibers pressed together in a thin sheet. Each of these fibers is a tiny tube, about 100 times as long as it is wide. Today, most fibers come from wood, though in earlier times, the source was more likely to have been rags of linen or cotton. The length of wood fibers from conifers is about 0.13-0.25 in (0.33-0.64 cm), and from hardwoods, about 0.04 in (0.10 cm). Other vegetable fibers are much longer. Cotton fibers, for example, may be one or more inches in length, with diameters of 0.02 in (0.05 cm). The source material is reduced to a slurry of fibers that floats freely in water, and many of the fibers will have been broken or cut when making the pulp. When the water is removed, the fibers form a thin layer of pulp which eventually becomes paper.