Full text of a lecture given by L. Tissot on 15 December 1943 at the Ecole Supérieure de Tissage de Lyon on how openwork (ajouré) effects can be produced on the loom. It covers empty dents and weftless passages, brocading with the brodeuse, false gauze, Lyon and English gauze, double-face, double-turn and card gauze, and the hand-loom techniques of Picardy: crocheted gauze made with the porte-aiguilles and Marly gauze. Figures include gauze weave diagrams and drafts, and the text describes warping, heddle (lisse) arrangement and treadle setup for each technique.