Basic Weaves and Fabric Structure
Basic Weaves and Fabric Structure
The exam tests the three foundation weaves, their drafting (draft plus lifting plan), and the effect of float length on lustre, strength and durability.
Foundations and derivatives
- Plain (tabby) 1/1: maximum interlacing, firm, cheapest, matte - used for gamosa grounds and poplin. Rib (warp/weft) and basket (matt, 2/2) are plain derivatives.
- Twill: diagonal lines; 2/2, 3/1 and 1/3 are common; longer floats give drape and lustre and the diagonal direction is set by the draft. Herringbone and diaper are twill derivatives.
- Satin/sateen: one binding point and long floats; a 5-end satin is warp-faced with a float over four, a 5-end sateen is weft-faced. Lustrous but snag-prone.
- Figured cloth: extra warp or weft, dobby (groups of ends) or Jacquard (individual ends).
Reading a draft
The draft shows which heald each end is drawn through; the lifting plan shows which healds rise on each pick. Healds needed = number of different lifting combinations in one repeat.
Worked example
Design a 2/2 twill. Mark a 4 × 4 grid: end 1 lifts healds 1–2, end 2 lifts 2–3, end 3 lifts 3–4, end 4 lifts 4–1, then repeat. The repeat is 4 ends × 4 picks, needs 4 healds, and each thread floats over 2. For a 3/1 twill the repeat stays 4 × 4 but the warp floats over 3, making the cloth warp-faced.
Marks-losing traps
- Satin is warp-faced, sateen weft-faced.
- A 5-end satin floats over four threads, not five.
- Twill direction (Z or S) reverses when the draft is reversed - read what the question asks.
- More interlacing means more strength but less lustre; do not claim plain weave is the shiniest.