Spirality is the tendency of the knit courses to rotate diagonally after washing, which makes the side seams of a T-shirt twist toward the front. It is tested according to ISO 16322: the specimen is washed, marked, and the displacement of the course line from the vertical is measured and expressed as a percentage.
Up to 5% is often accepted, and demanding brands ask for under 4%, but these are guidelines. Ask for the value measured after washing, not before. If garments twist, the cause lies in the fabric, not the workshop, so request the report and a test on the lot.
spiralitytwistingiso-16322
