Rags to be made into paper are first sorted, and any unsuitable ones are discarded. Seams are opened, and nonfabric materials, such as buttons, are removed. The rags are chopped into small pieces and then cleaned by boiling them in strong cleansing solutions. Next, they are rinsed and beaten while damp until all of the threads have disintegrated and the fibers float freely in water. This is the paper pulp.
The very dilute pulp is next sent to the vat where the paper will actually be made. A rectangular mold containing wires running at right angles to each other is used to make a film of the pulp. Traditional molds have thin, closely spaced parallel wires running across the mold at the surface. These are attached to thick, widely spaced wires beneath them that run in the opposite direction. Paper formed on this type of mold typically reveals a ladder-like pattern when held up to the light, and is known as laid paper. Woven paper is formed on a mold of plain, woven wire screening. Thin wire forming a design may be attached to the mold's surface wires to produce a watermark in the finished paper. A rectangular frame, called the deckle, is placed over the mold to convert the mold into a sort of tray.
The papermaker then dips the mold with the deckle attached into the vat of dilute pulp and draws up a small amount of pulp on the surface of the wire. The mold is then shaken and tilted until most of the water has drained through the wire. The deckle is removed, and additional water is allowed to drain off. A second worker takes the mold and transfers the film of pulp to a piece of damp felt, laying a second piece of felt across the top.
This process continues until a stack of alternating wet paper and felt has built up. The stack is placed in a press to eliminate any residual water. Then the paper and felt are separated, and the paper is pressed by itself and hung up to dry. When dry, the paper sheets are dipped in a tub containing size (essentially gelatin or very dilute glue) and dried again. This gives the paper a harder and less absorbent finish than it would otherwise have had.
All paper was made by hand until the early nineteenth century. Artists use most of the handmade paper consumed today, though hand printers can still be found who believe it the finest printing surface available.