Why a prototype's fit changes

A prototype exists to be wrong in useful ways. When the fit of a project changes between versions, that is the process working, not failing. Here is what moves it.

Three patterns, not one

Every garment here starts from a block: the plain, foundational shape with no seam allowances and no style lines. The block is tested and then left alone.

From the block comes a master pattern for the specific piece — every stitch line and cut line, the allowances, grainlines, notches, labels, and a version number with a note of what changed. The master is photographed and kept.

From the master comes a working pattern: a disposable copy that gets cut, pinned, drawn on and worn out. When it wears out, another is traced. The master does not get touched at the bench.

Fit changes are made at the master and recorded there. That record is what lets a second pair be cut the same as the first, or deliberately different.

What changed on the jean

The Standard Issue Jean block went through two muslins — quick fitting samples in cheap cloth — before any denim was cut.

• The first fit well overall but was slightly snug through the thighs and crotch, and pulled on a high step.
• The second was cut with the seam allowances drawn explicitly at 1.5 cm rather than eyeballed. Crotch comfort and mobility improved. The calves came out a little roomy.
• The decision from that: keep the upper leg of the second version as the basis, and taper below the knee if the leg needs it.

None of that would have shown up on paper. It showed up on a body, on a step.

Cloth moves too

A pattern that fits in muslin is not the last word, because the real cloth behaves differently:

• Shrinkage. Cloth that has not been pre-shrunk gets smaller on its first wash, and not evenly in both directions. The pattern has to account for it, or the garment has to be sized and washed before it is measured.
• Relaxation. Denim in particular gives at the waist, seat and thigh with wear, then tightens again after a wash. A jean is measured after it has been worn and washed, not fresh off the machine.
• Seam allowance behaviour. A flat-felled seam, a bound seam and a plain pressed-open seam take up different amounts of cloth. Changing a construction detail can change a finished measurement.

What that means for the numbers on this site

Finished measurements get published when a version is stable enough to repeat. Until then a project page says which prototype it is and what stage it is at — and the revision is part of the record, not something to hide. How those stages and numbers are marked on the piece itself is explained under Workshop marks.