A theoretical framework is given for the experimental results obtained by Cednäs on the changes in dimensions of set and non-set wool woven fabrics during processing. The resistance to dimensional changes is related to the yarn curvatures. The magnitudes of the dimensional changes during wetting and drying are discussed in terms of change of the set curvature of the yarn. Experimental results are given on the curvature set into hair fibres, and it is shown that the setting results obtained may be explained in terms of an Eyring Flow Element model. Further, it is shown that a similar model serves to describe the dimensional changes of the set and non-set gaberdine fabrics described by Cednäs.