An expression is derived which relates the tension changes which could take place in a fabric held at fixed dimension to the changes in the tensile modulus and dimensions of the component fibres when their moisture content is altered. The relative contributions of the longitudinal and lateral swelling of the fibres, and the extent to which these influences are dependent upon the geometry of the fabric, can be deducted from this expression. Qualitative verification is provided by measurements of sequential tension changes throughout cycles of wetting and drying of a series of viscose and acetate fabrics of selected construction. The direction of the sequential tension changes at fixed dimension were shown to be opposite to the direction of dimension changes at fixed tension. However, the tension changes were reversible, while the dimension changes were not, presumably, owing to the restraints imposed by inter-fibre friction. Quantitative relationships between the magnitude of the dimension changes and fabric geometrical factors have not yet been established. However, a qualitative understanding of the mechanisms through which fabric shrinkage is related to and affected by fibre properties and fabric geometry has been attained.