Making Paper from Wood Pulp — The Groundwood Process That Made Paper Cheap

For nearly two thousand years, paper was made from rags — worn-out linen and cotton beaten to pulp. It was good paper, but rags were scarce, and as literacy spread the world simply ran out of them. The answer, found in the 1840s, was to make paper from the most abundant fibre on Earth: wood.

The simplest method is mechanical groundwood pulp. A log is pressed against a wet, spinning grindstone, which tears the wood into a slush of short fibres. Screened, refined, and matted on a wire, those fibres dry into paper. It is fast and cheap and turns a forest into newsprint — which is exactly what put a daily newspaper into every household.

Groundwood pulp keeps the wood's lignin, so the paper is weak and yellows with age, as old newspapers show. Removing the lignin by chemical pulping gives the white, durable paper of books — a more advanced step that built on this one. But it was cheap wood paper that truly democratised the printed word.