Installment of Posselt's "Fabric Analysis" series covering yarn twist: why twist is applied, how much is used for singles and folded cotton yarns, and how twist direction affects fabric appearance. It explains open-band and cross-band twist, how twist direction relates to twill line prominence, and how to test twist and measure contraction (take-up), including a description of the Knapp twist counter. Includes a table of turns per inch for 2-fold cotton yarns from 2/20 to 2/200.