Textile Structure
how cloth is put together
Concept

Condemned area — where it appears

The cloth a fault costs, which is not the cloth the fault occupies: a fault condemns whichever cut piece it lands in. So the cost depends on the size of the pieces being cut as much as on the fault, and the same roll can be excellent for shirts and unusable for coats.

Named by 5 essays across 2 fields — each of them below, with the objects they name alongside it.

Three places a mistake can be made, and three shapes it leaves. A loom holds a design in three separate objects, and a single mistake in each of them produces a fault of a completely different size — not because the mistakes differ, but because of how many intersections each object controls. On a 50 m piece of muslin 1500 mm wide, holding 396,000,000 intersections: one end drawn on the wrong shaft is wrong at every pick for the whole length, 110,000 of them; one pick made in the wrong shed is wrong across the whole width once, 3,600; and one shaft tied wrongly to one treadle is wrong wherever that shaft's ends meet that treadle's picks, which is everywhere — 6,187,500, or 1.6% of the cloth. The ratio between the extremes is 1719 to one, and the largest of the three is the one nobody sees happen, because every thread is exactly where it should be.

Three mistakes and the shape each one leaves

A loom holds a design in three separate objects, and one error in each of them is the same size of error. What they cost differs by a factor of seventeen hundred — and the largest of the three is the one nobody can see happening, because every thread is exactly where it should be.

fancy · Shafts The same fault in the warp and in the weft. A 50 m piece 1500 mm wide, with a 3-thread fault in each direction. The width is drawn 9.3 times over scale so that the piece is a rectangle rather than a line, and the two faults are drawn as marks rather than at their own widths, which at this scale are a fifth of a pixel. They have the same cause size — 3 threads — and they condemn 0.063 m² and 0.0020 m² respectively, a ratio of 31 to one, because a warp fault runs the length of the piece and a weft fault runs its width. That ratio is the aspect ratio of the piece and nothing else, so it is a property of how cloth is made rather than of what went wrong. It is why a broken end stops the loom and a mispick often does not, and why the two faults are priced by every grading scheme as though they were different kinds of thing.

A missing end is a fault the length of the piece

A broken end and a mispick are the same size of accident — one thread — and they condemn areas that differ by a factor of thirty. The ratio is the aspect ratio of the piece and nothing else, which makes it a fact about how cloth is made rather than about what went wrong.

applied · Faults How much of an abrasion loss is not damage. The share of a reported abrasion mass loss that is hair rather than cloth, for sheeting as woven and raised 64-fold. The first material off a fabric is its hair layer, which is 0.107% of a bare cloth's mass and 6.84% of a napped one's — and which regenerates, so it keeps coming off. A bare cloth is through it by 5344 cycles and the test then reaches the crowns, where the loss means damage. A napped cloth is not through it by 342000, which is more cycles than any standard test runs, so a Martindale on a fleece never measures the fabric at all. Two cloths taken to the same mass loss have therefore not lost the same thing, and the more heavily napped one may not have been damaged. a-cloth-loses-its-strength-before-its-mass made the same point about a different pair of quantities; this is the same failure one layer further out.

Abrasion takes the hairs first

An abrasion test reports milligrams lost against cycles, and the first milligrams off any fabric are not fabric. On a bare cloth that stage is over in a few thousand cycles. On a napped one it is not over by the end of the test, so a Martindale on a fleece never measures the fleece.

applied · Damage What the four-point system charges for a fault, and what the cutting room pays. For a single warp fault of each length: the points the four-point system scores it — one up to three inches, two to six, three to nine and four beyond — and the number of 900-millimetre panels it condemns. Below a panel's length every fault condemns exactly one panel while its points run from one to four, so the scheme charges four times as much for a fault that costs the same. Above a panel's length the panels grow without bound and the points stay at four, so the scheme stops charging exactly where the cost starts rising. A ten-metre fault scores 4 and condemns 12 panels. What the chart cannot show is the marker, which decides the panel size and therefore the whole of the second curve.

A grade charges by the length and a cutter pays by the panel

The four-point system scores a fault by how far it runs — one point to three inches, four beyond nine — and caps a linear metre at four points however many faults it holds. A cutting room pays by how many panels the fault lands in. Below a panel's length every fault costs exactly one panel while its score runs from one to four; above it the panels grow without bound and the score does not move at all. Two fifty-metre pieces built to the same 267 points a hundred square metres lose 33 per cent of their panels and 92.

applied · Faults The first 12 metres of a bolt, cut three ways. A bolt of 50 metres carrying 40 faults, with its first 12 metres drawn: the fault positions above, and below them the 900-millimetre panels a cutter gets cut blind, cut with the same rigid tiling slid to its best offset, and cut around the faults with the map in hand. Over the whole bolt the three yield 28, 30 and 40 sound panels of 55. Sliding the tiling buys 2; breaking it buys 12, which is 43 per cent more cloth from the same roll. What the strip cannot show is the width, across which the same argument runs again with a different panel dimension.

A fault map is worth most where the grade is worst

A cutter who knows where the faults are can slide the marker or break it, and only one of those is worth anything: sliding a rigid tiling to its best offset recovers two panels of fifty-five, and letting the tiling break recovers twelve — two panels in five more cloth from the same roll. The gain has a maximum in the middle of the range, because there is nothing to recover on a clean bolt and nothing to be done on a ruined one. And the prediction the grading essay made, that a map is worth most on a bolt whose faults are bunched, is false: bunching leaves clear runs for the blind cutter too.

applied · Faults

Named alongside it

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

FaultMarker efficiencyMeasurementSpecificationBroken endPoisson fieldAbrasionCanopy criterionDamageHair balanceHair layerHarness

All concepts