Lesson 2 of Posselt's textile school series on designing and fabric structure for harness work. It introduces the three foundation weaves (plain, twill, satin), the idea of the weave repeat, and the plain weave with its fabric properties and repp variations. The lesson then covers the construction of twills, with even-sided and uneven-sided twills enumerated for 3 to 8 harnesses, illustrated with point-paper diagrams (Figs. 10-49). It closes with review questions for students.