Fabric defect · Woven fabric - Starting marks, set marks and stop marks

ConductVision Textile is designed to flag each defect with its place on the roll, its size, its points and a still image. Your inspector names the defect and confirms or dismisses it.

On the defect map in the roll report, a starting mark is a line across the width.

Goldberg's 1950 casebook defines set marks, or start-ups, as "narrow fillingwise bands where there are more than the normal number of picks per inch" ¹. A U.S. federal glossary gives both sides. Its heavy place, which it also calls a bad set mark, stop mark or starting mark, is "a fillingwise band or bar either across the full width of the cloth or a portion of it" with thicker picks or more of them; its light place, a starting mark on the light side, has finer picks or fewer ².

A 2015 study of loom restarts describes both: the first pick after the restart may not beat fully into the cloth and leave a sparse mark, or lie too close to the picks before it and leave a dense one ³. A 1968 study adds the mark left after mending, "lateral bars which show up near the cloth-fell when a loom is re-started after defects in the cloth have been removed" ⁴. Knit fabric has its own stop mark, "a horizontal fabric streak caused by a tension difference when the knitting machine is stopped" ⁵.

Starting marks can hide in the greige. Goldberg notes that these pickage variations "will not be noticed until the goods are dyed and finished," when uneven dye penetration shows narrow bands where the fabric is denser ¹. In one of his cases a band that looked like a shade fault was a set mark: "Where the pick count was high, the dyestuff penetration was less and there was a very narrow light band" ¹. In another, set marks with far fewer picks than normal left the cloth so open that singeing flames shot through and burned small holes ¹.

A starting mark runs across the width, across all of it or part of it ². It sits where the loom stopped ¹, and a 1968 study concluded that "there is something which produces set-mark at the start as well as at a stop" ⁴.

Along the roll the band can be narrow. In Goldberg's case it "was never more than about 1 inch in width, the pick counts gradually returning to the normal" ¹.

A starting mark is scored by its length: 1 point up to 3 inches, 2 points over 3 up to 6 inches, 3 points over 6 up to 9 inches and 4 points over 9 inches ⁷. A mark across the full width is longer than 9 inches, so it scores 4 points. Under the 4-point system, no linear yard or metre gets more than 4 points, however many defects it holds ⁸.

A 1968 study of warp tension set out three kinds of thick and thin places that weaving leaves: waviness, set marks, and starting places after mending. It held that "only waviness and set-mark are mechanically preventable," and proposed that set marks come mainly from warp tension at a start or a stop that differs from steady running ⁴.

A 2015 conference paper traced start-up marks to the cloth fell creeping out of place while the loom stood. It noted that compensating for that movement after the restart "is also an effective method widely used now" ³.

A 2015 study of a narrow fabric loom weaving elastic tape treated start-up marks as a major defect in woven fabric, and carried out a mathematical analysis of the loom both running and stopped ⁶.