Paper is made of tiny fibers. Most come from trees. Paper made with long fibers is stronger. Spruce and other cone-bearing trees have long fibers, so mills like them. The wood is cooked into a soft, wet mix. It is called pulp.

To make a sheet by hand, a papermaker dips a screen in a vat of pulp. Then she lifts it out. Water drains through, and a thin wet sheet is left on top. Paper made by hand has soft, uneven edges. They come from a wooden frame called a deckle.

A paper machine does the same job again and again. A moving belt of fine mesh carries the wet pulp. The water drains away. The wet sheet is squeezed between rollers and dried with heat. It comes out as a long sheet, wound onto huge rolls.

Mills add a coating called size. Without it, paper soaks up ink like a blotter. At the end of the machine, paper is rolled between hard metal rollers. These are called calenders. They make the paper smoother and flatter.

Paper can be bleached to make it whiter. Mills also mix in chalk or clay. A big paper machine can have from 40 to 70 steam-heated drums. They dry the paper.

As of November 2026, paper and cardboard make up about a quarter of the trash that Americans throw away. Americans recycle about 45 million tons of paper a year. Most cardboard in the United States is recycled. Old paper can be made into new paper.

Words to know

• pulp: soft wet mix
• deckle: wooden frame
• calenders: smoothing rollers
• size: paper coating