Weaving & Fabric Construction
Two different mechanisms, two different numbers. Lumping them together is how mills miss finished width.
— %
Reed to finished cloth
Reed-to-greige contraction is weft crimp and is set by the construction. Greige-to-finished depends on the process route and must be measured on your own range.
Fabric Contraction & Loom-state Shrinkage Tool — free, with the formula and a worked example, at Textile School.