Lesson XVII of a serial textile design course in Textile World Record, explaining how to design diagonal weaves by "filling drafting", alternating picks of a regular 45-degree twill with picks of the same twill started on a different pick. Worked examples use 8, 9, 10, 12 and 16 harness twills, with plates of drawdowns showing the foundation twills, the resulting diagonals and the pick-by-pick drafting sequences. Repeat sizes are given (e.g. 8 harness x 16 picks, 12 x 24, 16 x 32), and the method is presented as useful for woolen and worsted fabrics.