Solid fraction — where it appears
Named by 3 essays across 2 fields — each of them below, with the objects they name alongside it.
How dense a knitted fabric is
A fabric's areal weight is what the trade specifies and it says nothing about bulk. Divide it by a thickness and the answer is a density — 0.40 grams a cubic centimetre for a jersey, a quarter of the fibre it is made of — and that quarter, the share of the volume that is not air, is the number every other property follows.
A knit is warm because of where its yarn is not
Warmth is a thickness of still air, and until a knitted fabric had a thickness there was nothing to compute. It has one now, and the answer is that a rib's warmth is a machine setting: opening the beds from two diameters to five nearly trebles the fabric's resistance without changing a gram of yarn.
A weight fixes the fibre and not the drape
Every plain cotton cloth of 150 grams a square metre contains the same fibre, and the count decides only how it is arranged. Across the counts that can make that weight, thickness rises threefold and cover falls in step, so their product holds still. The bending length does something stranger: at the bound a woven yarn actually sits near, it depends on neither the count nor the weight, only on the fibre.
Named alongside it
The objects these essays reach for when they reach for this one.
Areal densityCloth thicknessLoop lengthNeedle bedSpecificationTightness factorTwo-bedBending lengthBending rigidityConductivityCover factorCrimp