Stitching — where it appears
Named by 8 essays across 3 fields — each of them below, with the objects they name alongside it.
Backed and stitched constructions
A double cloth is two fabrics woven at once, and the check that verifies it says exactly two. Turn one intersection over and it says one — which means one mistake is enough to destroy the construction, and the enumeration says half of them would do it.
Velvet is cut apart
Two ground cloths are woven face to face with a pile warp shuttling between them, and while it does the whole thing is one cloth — the criterion says so, and the pile is the only reason it is true. Then a knife runs down the middle and the same criterion says two. The manufacture is the deliberate destruction of cloth integrity.
A tube and two cloths are the same draft
Two separate fabrics, a cloth twice the width of the loom and a seamless tube are the same draft to the last square. The check this site is built on reports two layers for all three and is right every time — because the thing that separates them is four free selvedges, or two, or none, and a repeat has no selvedges in it.
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.
An interchange joins what a stitch would have had to
The rung below spent a whole essay on where a stitch may be put in a double cloth, and found face weaves with nowhere to put one at all. A design in which the two layers change places from block to block needs no stitch anywhere: the boundary is the join. Two blocks side by side make one cloth with not a single intersection reversed, and the same two blocks with no boundary between them make two.
A double cloth is only softer if its yarn is set
A double cloth is sold as weight without stiffness: two light cloths in place of one heavy one. Divide the same yarn into two layers and the cloth is √2 or twice as thick, but at the free end of a yarn's stiffness bracket — where an unset yarn sits — its bending rigidity does not move at all, because it is the number of fibres across the width times the stiffness of one. Only a set yarn makes the double cloth the softer, and stitching the layers together pushes it the other way.
A crease cannot cross a seam
The outer layer of a folded stack has further to go than the inner, by the fold's angle times the stack's own thickness. A four-layer seam of quarter-millimetre cloth taken through a half turn needs its outer layer to be 2.45 millimetres longer than its inner — and a stitch line every three millimetres has pinned them. So the fold opens out where it crosses the seam, which is what a trouser crease visibly does, and the arithmetic gives the radius it opens to.
A stitch takes back what the parallel rule cannot see
Dividing a cloth's yarn into two layers makes it warmer than its thickness, and the essay that found it computed the warmth by the one mixing rule that cannot see a stitch — the one that treats every fibre as though it ran straight through the cloth. That rule gives the largest bonus there is. Yarn in a cloth lies in its plane, and by the rule for fibres lying across the heat's path a double muslin's bonus is 8.4 per cent, not 18.8. A stitch is the one fibre that does run through the cloth, and at half the intersections it takes the whole bonus back.
Named alongside it
The objects these essays reach for when they reach for this one.
Double clothCloth integrityConnectivityBacked clothCloth thicknessPoint paperStitching planTubeBending rigidityBlockCantileverCovering rule