Linen is a natural vegetable fibre derived from the inside of the woody stalk of the flax plant, an annual of the family Linaceae. There are over two hundred varieties, but commercially grown flax comes in two main types - long-stalked flax, grown for fibre, and crown flax, which is grown for seed. In northern countries it is sown in the spring, and harvested in late July or August, when the stalks begin to turn pale yellow at the base, and the seeds turn brown.

The flax plants must be pulled up by the roots, rather than cut, both to preserve the length of the fibres (the longer the fibre, the better the quality of the yarn), and to avoid losing the sap and weakening the fibres.They are then stacked leaning against each other wigwam-fashion to dry and season. The flax is then threshed, or “rippled”, by pulling it through large combs to remove the leaves and seeds.

Next the fibres must be separated from the outer bark and the gummy inner pith. These must first be partially decomposed to make them soft enough to be removed without damaging the fibres, a process known as retting. This used to be, and sometimes still is, done by laying the plants out in the fields exposed to dew and rain, or by immersion in pools or streams, but nowadays it is more commonly done in vats using a solution of chemicals. This process is faster and easier to monitor than traditional methods, although many people believe that these produce a better quality of yarn.

After retting the plants are dried, crushed between fluted rollers to break up the bark, and then beaten with rotating paddles (”scutching”) to remove the debris.

The linen fibres can now be prepared for spinning into yarn. They are laid out roughly in parallel and drawn through a series of increasingly fine combs (”hackling”), which removes shorter lengths of fibre, called tow, that are used for cheap linens, or for making rope or twine, and stretches and straightens the long fibres, known as line, that are used for damasks and other high quality linens. These are then passed through rollers that lay them out in parallel with their ends overlapping, ready for spinning.

Coarse linens may be spun dry, but fine linens need to be spun in a humid atmosphere to prevent breakage and ensure an even yarn.