Textile Structure
how cloth is put together
Concept

Add-on — where it appears

The mass of coating or finish a cloth carries per square metre, over and above its own weight. The add-on needed to reach a given depth is the volume between a cloth's crowns and that depth, which is why a rough face costs more coating than a flat one.

Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.

What it takes to bury a cloth's crowns. The film needed to fill a fabric's surface to a stated level, for plain, 2/2 twill, satin 8 in sheeting, at a film density of 1.2 g/cm³. Burying the crowns entirely takes 187 g/m² on the plain, 186 g/m² on the 2/2 twill, 183 g/m² on the satin 8 — and the ordering is not the ordering of roughness. A weave with plateaux presents a wide flat top that a thin film covers, and a weave with points presents crowns with valleys between them that the film has to fill before it is continuous anywhere. Every gram spent filling a valley is a gram that is not bridging a hole, which is where a coated cloth fails.

A coating fills the crowns before it bridges the holes

A film does not sit on a cloth, it fills it — and the volume it has to supply to reach a level is the integral of one minus the bearing area. Burying an ordinary sheeting's crowns takes 185 grams a square metre, which is more than the cloth weighs, and the whole of the weave's influence is spent in the first ten of them.

finishing · Coating What a film 80 µm deep touches on a sheeting. The part of a sheeting that a film reaching 80.3 µm below the crowns touches, in plan over two repeats each way, for a 2/2 twill and a 2/2 hopsack. On the 2/2 twill the film is separate patches, and joins at 161 µm, an add-on of 116 g/m² of the 186 that flattens the face; on the 2/2 hopsack the film is separate patches, and joins at 161 µm, an add-on of 116 g/m² of the 186 that flattens the face. The twill's crowns join edge to edge in its matrix and not on the cloth, because two neighbouring ends are separated by the gap the sett leaves.

A ridge in the matrix is not a ridge in the cloth

A 2/2 twill's crowns join into a ridge across its matrix and a 2/2 hopsack's are islands, so a thin film on the twill should be continuous from the first gram and on the hopsack a scatter of patches. Laid on the cloth's own surface rather than its matrix, both films are patches — the twill's ridge crosses from one end to the next, and between two ends lies the gap the sett leaves. On a sheeting both join at the same depth, 116 grams into the 186 that flatten the face, and the weave's whole influence is a window of up to 27 grams at the setts where it opens at all.

cloth · Surface

Named alongside it

The objects these essays reach for when they reach for this one.

Bearing curveCoatingCrown lineCover factorFilmOpening sizePercolationSettSurface height

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