Paper may be made from rags, rope, straw, grass, and wastepaper, but the most common source of paper, by far, is wood.
Wood from trees is taken to a paper mill, where it is cut into chips. These chips are put into huge vats, where they are boiled and stirred with chemicals until they become a soggy mush, called pulp.
Next the pulp is washed and bleached to make the paper white. Then a filler of clay or chalk is added. The product at this stage is called stuff.
For cheap newsprint paper, wrapping paper, and wallboard, the procedure ends here, and the paper is wrapped and shipped as the rolls come off the paper machine. For better grade papers, the kind used for writing, for example, a smooth finish is needed. This is obtained by adding cotton and other rag fibers to the paper and passing it through a stack of heavy (30 ton) polished rollers.
The stuff is then emptied into a refining machine, with a long belt made out of a screen. The water drains off through the screen, and the remaining fibers mesh together into a thin sheet. This sheet then passes through a series of felt-covered rollers which press the remaining water out of the freshly-made paper, dry it, and turn it into a long sheet of paper.
The most expensive paper in the world, a handmade writing paper from Finland, sells at Cartier’s in New York for $8,000 for 100 sheets. Yes, envelopes are included!