Fabric Structure and Weave Design
This domain examines how interlacing patterns, repeat size, float length, sett and crimp determine fabric appearance, cover and performance, and how weave plans are drafted.
Core rules
- Plain weave: 1/1 interlacing, shortest floats, maximum firmness. Rib and basket are derivatives with grouped ends or picks.
- Twill: diagonal lines; 2/2 twill has a 4 × 4 repeat and two intersections per end per repeat. Twill direction and balance affect appearance.
- Satin: warp-faced, long warp floats, one intersection per end per repeat. Sateen is weft-faced. Five-end satin with a move of 2 or 3 is common.
- Repeat = least number of ends and picks that repeats the pattern. Draft shows ends through healds; peg plan or lifting plan shows heald frames per pick. They must match.
- Crimp is the extra yarn length in fabric compared with the straight length. Interlacing frequency raises crimp and affects cover, extensibility and yarn consumption.
- Cover factor for cotton: K = threads per inch / square root of Ne. Maximum cotton cover factor is about 28.
Worked example
Plain weave cotton, 40 Ne warp and weft, 60 ends/inch and 60 picks/inch. K warp = 60 / square root of 40 = 9.49. K weft = 9.49. Cloth cover factor = 9.49 + 9.49 - (9.49 × 9.49 / 28) = 15.76. This indicates an open-to-moderate cloth, not a maximum-cover fabric.
Traps
- Reversing satin and sateen faces.
- Counting floats instead of intersections when building a draft.
- Using finished sett when the calculation requires greige sett.
- Ignoring crimp in yarn consumption.
- Mismatching draft and peg plan so the weave cannot be woven.