Reed substitution calculator

Find a repeating ends-per-dent sequence and see the sett it actually produces.

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How the calculation works

achieved EPI = reed DPI × sum(ends in repeat) ÷ dents in repeat

A mathematical match does not prove yarn will fit through a dent or that the cloth will be uniform. Up to 32 dents per repeat are searched, with at most eight ends per dent. Rigid-heddle slot/hole threading has different constraints; do not apply this sequence blindly.

Full calculation methodology

Worked example

For 20 EPI in a 12-dent reed, repeat 1–2–2 ends per dent: 12 × 5 ÷ 3 = 20 EPI. This matches Schacht’s worked example.

Use the complete weaving planner to connect the dimensions, allowances, and yarn quantities for one project.

Reference: Schacht reed substitution. Calculations run locally.

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