Topic summary
Twill weave
Extracted from the Wikipedia article Twill.
Structure
Twill weave is often designated as a fraction, such as 2⁄1, in which the numerator indicates the number of harnesses that are raised (and thus threads crossed: in this example, two), and the denominator indicates the number of harnesses that are lowered when a filling yarn is inserted (in this example, one). The fraction 2⁄1 is read as "two up, one down" (the fraction for plain weave is 1⁄1.). The minimum number of harnesses needed to produce a twill can be determined by totaling the numbers in the fraction; for the example described, the number of harnesses is three. Twill weave can be identified by its diagonal lines.