Textile Structure
how cloth is put together
Concept

Plain weave — where it appears

The weave in which every thread passes over one and under one, which is the most interlaced cloth there is. Being the most interlaced makes it the firmest cloth and also the one that must be set most openly, which are the same fact twice.

Named by 9 essays across 4 fields — each of them below, with the objects they name alongside it.

The 5-end satin. The 5-end satin on point paper, a filled square meaning the warp is on the face. Its longest float, its interlacing count and the number of separable cloths it describes were all counted from the matrix that drew it.

Plain, twill and satin

Three rules, and everything else in weaving is a variation on them. What separates the three is not appearance but one trade — how often a thread changes face against how far it runs when it does not.

weaves · Foundation weaves 2/2 twill: written at 4×4, repeating on 4. On the left the draft as written, with the smallest rectangle that tiles it outlined. On the right the same draft with every translation that leaves it unchanged marked from the top left corner: there are 4 of them, so a fundamental domain holds 4 intersections rather than the 16 the rectangle claims and the 16 the point paper carries. Nothing in the drawing on the left says so.

What a repeat repeats

Point paper is ruled in squares, and the rectangle a draft is written on is a decision by whoever drew it. The unit a cloth actually has is smaller — two intersections for a plain weave, four for a 2/2 twill — and it is not a rectangle at all.

cloth · Repeat What a raising machine can catch in a 2/2 twill. The draft with every weft float long enough for a raising wire to lift marked on it. The teeth need an unsupported length of thread on the surface, so a cloth in which every thread is bound at every crossing offers them nothing at all — which is why a napped fabric is always a twill or a satin and never a plain weave.

Only a float can be raised

A raising machine drags wire teeth across a cloth and pulls fibre ends up into a nap. The teeth need something to catch, and what they catch is a float — so which fabrics can be napped at all is a question about the matrix, decidable exactly, and the answer over the whole four-by-four census is two.

finishing · Nap Where a stitch can hide on a 5-end satin face. The face weave on point paper, with a mark on every gap between two ends at which a stitch would be covered. 15 of the 25 positions in the repeat pass the cover rule, which is 60 per cent of them, and 5 of those can be used at once without two stitches sharing a pick or a gap.

Where a stitch can hide

One reversed intersection turns two cloths into one, and half the intersections in the repeat would do it. Almost none of them may be used — a plain-faced double cloth has nowhere at all to put a stitch, a five-end satin has fifteen places or none depending on which rule is asked, and two satins of the same order differ by a factor of two.

fancy · Double cloth Plain weave, doubled. Plain weave, then the same weave with its picks grouped in 2, its ends grouped in 2, and both — which are a warp rib, a weft rib and a hopsack — and a 2/2 twill beside them for comparison. The rules under the drafts bracket the threads that lift together on every pick and so lie touching. Each doubling multiplies the cloth's own unit by 2: 2, then 4, then 8 intersections. The hopsack and the twill interlace equally often and are drawn from different rules. The setts under each draft are the densest that weave may be set at with a 0.25 mm yarn, and a rib's two are 0.750 apart where every other weave here is square.

A cord is a stripe with no colour in it

Warp rib, weft rib and hopsack are plain weave with its threads doubled, in the warp, the weft, or both. Six of the nine measures this site takes off a matrix cannot tell a 2/2 hopsack from a 2/2 twill, and the three that can are not the ones a weaver quotes.

weaves · Rib weaves The selvedge turns of a 2/2 twill, 4 ends wide, from the left. A strip of 2/2 twill 4 ends wide over 8 picks, the first thrown from the left, with the weft's turn between every pair of picks drawn at the edge it reaches. 0 of the 8 turns are caught, where the edge end is on the other face on the second pick, and 8 slip. Across all its edge placements the weave catches every turn at 8 of 16. What the drawing cannot show is how far a slipped loop travels, which the beat-up and the weft tension decide.

A selvedge holds only where its edge end changes face

A shuttle weft goes out on one pick and back on the next, and between them it turns round the end at the edge. The turn is caught only if that end is on the other face on the second pick; otherwise the loop has nothing to wrap and slides off. Plain weave catches every turn at every width. A 2/2 twill catches them at half its widths, and only if the first pick is thrown from the right side. A 3/1 twill, a hopsack and every satin catch them nowhere, and of the 22,874 four-by-four drafts, 9,636 cannot hold a selvedge at any width at all.

weaves · Firmness The selvedge turns of a 2/2 basket, 8 ends wide, from the left. A strip of 2/2 basket 8 ends wide over 8 picks, the first thrown from the left, with the weft's turn between every pair of picks drawn at the edge it reaches. 4 of the 8 turns are caught, where the edge end is on the other face on the second pick, and 4 slip. Across all its edge placements the weave catches every turn at 0 of 16. What the drawing cannot show is how far a slipped loop travels, which the beat-up and the weft tension decide.

A weave holds its selvedge with two of its own columns, or not at all

A selvedge holds where its edge end changes face at every turn of the weft there, and the turns at one edge fall on alternate pick boundaries. So an end can hold the right edge only if its column changes face at every odd boundary, and the left edge only at every even one. Whether a weave can hold a selvedge is then whether its set of columns contains one of each kind, and nothing about its width matters. Two ends re-entered on the right shafts make 13,238 of the 22,874 four-by-four drafts hold at any width, where 3,262 did. The other 9,636 need a shaft of their own. A weave with an odd number of picks has no column of either kind, and never can.

weaves · Firmness The tucked-in edges of a 2/2 twill, 8 ends wide. A strip of 2/2 twill 8 ends wide over 8 picks, woven with tucked-in edges: every pick is cut at both edges and each tail is laid back into the next shed, so between every pair of picks there is a turn at both edges. 8 of the 16 tucked turns are caught, where the edge end is on the other face in the next shed, and 8 are not. Across all its edge placements the weave catches every tucked turn at 0 of 16. What the drawing cannot show is the tail itself, which lies alongside the next pick for the tuck's length and doubles the weft there.

A tucked-in edge asks every weave the odd repeat's question

A shuttle weft turns at one edge per pick, alternately, and that alternation is what let a 2/2 twill hold both selvedges with two ends re-entered on its own shafts. A rapier or air-jet loom cuts every pick at both edges and tucks both tails into the next shed, so every boundary between picks is a turn at both edges — the question an odd repeat always asked. Only a plain column answers it. Of the 22,874 four-by-four drafts, 10,382 can still hold their edges on their own shafts, against 13,238 under a shuttle; the 2/2 twill is among the 2,856 lost. And the tucked zone carries two picks in every shed, which lies flat only below between a half and two thirds of a weave's maximum pick density.

weaves · Firmness One warp feed, in the body and in a tucked zone of plain weave. A section along one warp end of 20 tex cotton, in plain weave woven at 70 per cent of its maximum pick density, in the body of the cloth and in the tucked zone with two picks to a shed. Both ends are fed the same length per pick, so the zone's end rises only 0.124 mm against the body's 0.161 mm, and the weft takes up the difference. The cloth is 0.341 mm thick in the body and 0.377 mm in the zone, 11 per cent thicker. The climb between crossings is drawn smooth rather than as the model's arcs and tangent.

A tucked edge stands proud because its warp goes straight

A tucked zone holds two picks in every shed, and the obvious account is that the pairs run out of room and bulge. The loom says otherwise: the warp is let off as one sheet and the cloth taken up at one speed, so the zone's ends have only the body's length to spend. They rise less. The weft takes up the height, so the edge is proud well before the pairs stop fitting, and they stand up well after the count says they must.

weaves · Firmness

Named alongside it

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

FloatCensusSelvedgeInterlacingSatinFirmnessFundamental domainJammingLifting planPick densityPoint paperTwill

All concepts