Woven Fabric Reverse Engineering from GSM and Sett

The reconstructed GSM is printed so the balance can be seen to close; it should equal the measured weight exactly, and it will, because the counts were derived from it. That is a check on the arithmetic and not on the answer. What decides the answer is the count ratio, which the mass balance cannot supply - the same weight, sett and crimp are consistent with a coarse warp and a fine weft or the reverse, and only the ratio separates them. Take it from the fabric type, from a comparable specification, or by unravelling and weighing a measured length of each in the one case where certainty is needed. Crimp is the next most sensitive input and the one most often guessed. It should be measured on threads withdrawn from the swatch and straightened under a defined tension, since guessing it wrong moves the derived counts directly, and warp and weft crimp trade against each other in a way that a single assumed pair will get wrong for any fabric not woven at ordinary tensions. The whole calculation assumes the weight is yarn: a fabric carrying a resin, a coating, a heavy softener or residual size will return counts finer than the truth, because the mass balance credits the finish to the yarn. Desize and scour before weighing where the finish is substantial.