What do seam allowance and mixed sizes do to marker efficiency, and what does that do to a garment's cloth cost?

research/garment-markercost

A 1 cm seam allowance cut the stylised shirt's marker efficiency from 0.69 to 0.63 and the skirt's from 0.71 to 0.51; mixing three sizes in one marker shortened it 9%; swapped into the cost model, trench cloth rises from $26 to $33–41 at $7/m². Stylised; sensitivity, not a coat measurement.

6 tests

What it found

Follow-up to the nesting and cost-teardown projects. Adding a 1 cm seam allowance to stylised pieces lowered marker efficiency from 0.69 to 0.63 for a shirt and from 0.71 to 0.51 for a four-gore skirt (the skirt mostly loses its interlocking gores); nesting three shirt sizes in one marker was 9% shorter than three separate markers. Swapping the measured efficiencies into the teardown formula moves a $7/m² trench’s cloth cost from $26 (assumed 0.80) to $33–41. Stylised: invented outlines, one ply, small annealing budget (differences of a few cm are noise), and the coats were not nested, so the cost step is a sensitivity, not a measurement.

A figure from its own output

Figure produced by research/garment-markercost: efficiency — garment-markercost/experiments/efficiency.svg, written by the project's own experiment code.

Paper, code and results

More in Engineered clothing

How much cloth does a cutting plan save by mixing sizes in one marker, and is the saving real?Cutting-order planning for a 3-size stylised shirt: laying several garments per marker saves 9–11% of cloth over one per marker; mixing sizes adds 0.4–3.7% in sample, but re-nesting the chosen markers with fresh seeds leaves +0.09%, so it is within nesting noise. Stylised; invented shapes.
How far is a fixed 0.80 marker efficiency from a nested coat, and what does the difference do to the cost model?Nesting a stylised coat's 10 shell and 5 lining pieces with a 1.5 cm seam allowance gives marker efficiencies of 0.68–0.73 (shell) and 0.59–0.68 (lining) at three cloth widths, below the fixed 0.80 in garment-teardown; its trench FOB moves +9% to +15% at the teardown's own areas. Stylised, preliminary.
How many clothing sizes does it take to fit a population, and does a regular S-M-L grid waste them?How many sizes fit a population? On a stylised synthetic bust/hip population (+-4 cm), an exact size run beats a regular grid by 12 to 25 points at correlation 0.9 but not on fresh people at correlation 0; greedy is within 3.7 points of optimal (stylised, preliminary).
How many clothing sizes does a stretch fabric save?How many sizes does a stretch fabric save? On a stylised synthetic bust/hip population, 10% usable stretch cuts the sizes needed for 80% fit from 6 to more than 8 down to 2 or 3; an idealised upper bound (preliminary).
How much comfort can an infrared-transparent or gating textile buy, and which fabric properties matter?Fanger/ISO PMV and a two-node model extended with fabric infrared transmittance, emissivity and solar absorptance: indoors, transmittance 0→0.8 is worth ~2.4 °C of comfort at 28 °C; in sun, absorptance dominates. Stylised; assumed fabric properties, no reference for the optical extension.
How far is the repository's two-node thermal model from an open-source implementation of the Gagge model?Cross-checks garment-thermal's two-node model against pythermalcomfort over 108 conditions: core temperature within 0.25 °C, skin temperature mean 0.6 °C (up to 2.1 °C) apart; a comparison of implementations, not of people.

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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.