Hems

What it is

A hem is the finished bottom edge of a garment. The raw edge is turned up once or twice and stitched through, and the depth of that turn — how far up the leg the fold goes — is a pattern decision. Deeper hems hang better and can be let down later; shallower ones are lighter and quicker.

The Standard Issue Jean carries a 5 cm hem: deep enough to be turned as a cuff and show the selvedge outseam, and deep enough that the leg can be shortened once without cutting.

Lockstitch or chainstitch

Two kinds of machine stitch turn up on a hem, and they behave differently.

• A lockstitch is what most sewing machines make: a top thread and a bobbin thread locked together in the cloth. It looks the same top and bottom, it stays flat, and it is what the rest of the garment is sewn with.
• A chainstitch is made by a single-thread or two-thread machine that loops each stitch through the last. It looks like a straight stitch on top and a chain of loops underneath. It has more give, and — because the loops take up thread differently from the cloth — as a raw denim shrinks the hem twists slightly and settles into the ridged, puckered edge that old jeans have. That is "roping".

The Standard Issue Jean's hem is lockstitched. The workshop sews on a domestic Singer, which is a lockstitch machine; a chainstitch hem needs a dedicated machine the workshop does not have. That is not a compromise to apologise for — a lockstitch hem is not a lesser thing, it is a flatter one — but it does mean no roping, and the fade at the hem stays even.

What it changes

The hem is the most-handled edge on a garment and the one most likely to need attention: it rubs on shoes and floors, and its topstitching fades and frays first. Because the turn is deep, a worn hem on a jean from here can be re-hemmed rather than patched. How the cloth's shrinkage affects the finished length is under Shrinkage and relaxation.