For knits, the usual tolerances requested in orders are roughly ±3% to ±5% in length and width after washing, but exact values depend on the brand, the fibre and the product. 100% cotton shrinks more than polyester blends, and a fabric that was properly relaxed in finishing is more stable. Garments with a washed look or plain cotton yarn may allow a wider tolerance.
Write the tolerance into your specification and build the shrinkage into the pattern. A 5% shrinkage can change the final size by almost a full size on a long shirt.
shrinkagetolerancespecification
