The interlacements of yarns in woven fabrics cause the yarn to follow a wavy path that produces crimp. Off-loom width of the fabric is determined by the percentage of the induced crimp. Therefore. the final width of the fabric will be less or surplus than required if crimp percentage is not precisely measured. https://www.spidertattooz.com/Air-Force-Embroidered-OCP-Sew-On-Officer-Rank-Insignia-Major/