Fulling
Also searched as: milling, waulking, tucking, walking, fulled cloth, boiled wool, fuller's earth
Fulling, also called milling, finishes woven or knitted wool cloth with moisture, warmth, soap or alkali and mechanical action so it shrinks, thickens and partly felts into a denser fabric.
In detail
Loom-state woolen cloth is open and loose. In fulling it is wetted with a soap or alkaline liquor, sometimes an acid one, and repeatedly compressed, beaten or tumbled. Wool fibers migrate and entangle, drawing the yarns together; the cloth shrinks in length and width, the weave is partly hidden under a felted surface, and the fabric gains mass per area, warmth, wind resistance and resistance to fraying. The operator controls the degree of shrinkage through time, temperature, pH and mechanical intensity, and the cloth is then washed and often raised and cropped.
The science and numbers
Fulling depends on the directional friction that drives felting: the overlapping cuticle scales of wool make a fiber slide more easily in one direction than the other, so repeated compression and release ratchets fibers along and entangles them. Moisture, warmth and soap or alkali swell and lubricate the fibers and speed the process, and some mills mill under acid conditions instead. Modern rotary milling machines drive the cloth in rope form between rollers into a compression chamber, and tumbling machines are also used. Shrink-resist treatments that degrade or mask the scales, as used for machine-washable wool, strongly reduce the response to milling, so superwash wool cannot be fulled in the usual way.
A practical example
A mill fulls two cloths woven from similar woolen yarns. One is milled lightly so its weave stays visible and crisp. The other is milled heavily until the weave nearly disappears under a dense, felted face suited to an overcoat, as in a melton. Both came off the loom as loose cloth; fulling set their final character.
What to distinguish
Fulling is controlled felting of an already constructed fabric, whereas felting from loose fiber makes a textile with no yarns at all. The same shrinkage mechanism is what ruins wool sweaters in a hot machine wash, so fulled cloth can still shrink further if mistreated. Fulling also differs from scouring, which removes grease from raw fiber, although historic fulling cleaned cloth as well.
Origins and history
Fulling is ancient. Roman fullers cleaned and finished cloth in workshops using stale urine and absorbent clays, and the clay called fuller's earth takes its name from this use in drawing grease out of wool cloth. In medieval Europe, water-powered fulling mills drove heavy wooden hammers, mechanizing the trade, while in the Scottish Highlands and Islands cloth was fulled by hand in waulking, accompanied by work songs. The English surnames Fuller, Tucker and Walker preserve regional names for the craft.
Related terms
Sources & further reading
- Woolmark: Wool processing
- Woolmark: What is the wool fibre?
- International Journal of Biological Macromolecules: Shrink-resist finishing of wool with a disulfide reducing agent and papain (Li et al., 2024)
Technical references reviewed 2026-09-22. Examples are illustrative. Industry organizations and manufacturers describe their own fields; their references are not independent product endorsements. Figures are approximate and depend on the stated test conditions.