Twill
Also searched as: twill weave, 2/1 twill, 2/2 twill, 3/1 twill, herringbone, drill, chino, serge, denim weave, diagonal weave
Twill is a weave in which interlacings step over by one yarn on each successive pick, producing diagonal lines called wales across the fabric.
In detail
Each warp end floats over or under at least two weft picks before interlacing, and the pattern shifts sideways every pick, so floats line up into a diagonal. A 2/2 twill shows equal warp and weft on the face; a 3/1 twill is warp-faced, showing mostly warp. The wale can run left or right, and reversing it at intervals creates herringbone. Longer floats and fewer interlacings than plain weave let yarns pack more closely, so twills can be denser, softer to drape and more resistant to tearing.
The science and numbers
Twill notation gives the number of picks a warp passes over, then under: 2/1, 2/2, 3/1 and so on, with a minimum repeat of three ends and three picks. The step, usually one yarn per pick, fixes the wale; changing thread density changes the wale angle, which is steep in gabardine. Fewer interlacings per unit area mean lower crimp and greater yarn mobility, so twills often drape more readily than plain weaves and allow higher thread densities. Research comparing weave structures reports that twill and satin fabrics differ from plain weave in stiffness, tensile and tear behavior, and one laundering study associated a cotton twill with lower microfiber release than satin, though fiber content was confounded.
A practical example
Examine the face of a pair of jeans: fine diagonal lines run upward, and the face is darker than the inside. Denim is typically a warp-faced twill with dyed warp and undyed weft, so the face shows mostly colored warp and the back mostly pale weft. Tracing one blue warp end under magnification shows it passing over three picks and under one before repeating.
What to distinguish
The diagonal line identifies twill structure, not fiber or quality. Twill does not guarantee durability, stretch or a particular weight. Some printed or brushed fabrics hide their structure, so inspect the reverse or ravel yarns to confirm. Wale direction and angle also depend on thread densities and yarn twist, not only on the weave plan.
Origins and history
A twill needs at least three sheds, and therefore at least three shafts on a harness loom, which places it one step beyond plain weave in loom complexity. That extra control produced a large family of named fabrics distinguished by twill ratio, wale angle and finish, including drill, serge, gabardine and denim. Precise first dates for individual fabric names are not established here.
Related terms
Sources & further reading
- CottonWorks: Weaving basics
- Heliyon: Effect of cotton-Tencel siro yarn twist multipliers on stiffness of plain, twill and satin fabrics (Afroz et al., 2022)
- Toxics: Influence of textile type, weight and detergent dosage on microfiber emissions (Julapong et al., 2024)
Technical references reviewed 2026-09-22. Examples are illustrative. Industry organizations and manufacturers describe their own fields; their references are not independent product endorsements. Figures are approximate and depend on the stated test conditions.