An International Correspondence Schools instruction paper (Serial 496) on the mechanical leno (gauze) attachments used on dobby looms. It explains the doup and standard harnesses, bottom and top doups, drawing in, reeding, and the slackener or easer for single-lift (close-shed) dobbies. It then covers double-lift (open-shed) dobbies with the jumper and yoke, harness-chain pegging plans, and the fixing and setting of these motions. It ends by comparing American and European drawing-in methods. Illustrated with numbered figures of harness and mechanism drawings and four chain drafts.