Fishnet — where it appears
Named by 3 essays across 3 fields — each of them below, with the objects they name alongside it.
Why clothes need darts
A flat cloth goes round a cylinder for nothing and cannot go round a sphere at all without shearing. The amount of shear is decided by the curvature, and when it exceeds what the threads allow, something has to be cut out.
A hemisphere costs one full turn
The total angle a pattern must remove to cover a hemisphere is exactly 360 degrees, and it is the same for a hat and for a stadium dome. What changes with the fabric is how much of that the cloth can supply by shearing instead of by being cut — and that is a property of the sett, computed from the angle at which its threads jam.
A hole with nothing crossing
A real leno holds its holes open by crossing one thread over another, which is a topological arrangement and cannot come undone. A mock leno makes the same holes by grouping threads that nothing separates, and everything about it is friction.
Named alongside it
The objects these essays reach for when they reach for this one.
DartDevelopableGaussian curvatureCoverCover factorDoupDrapeFloat lengthFrictionGauzeInextensibleLeno