A revival of interest in woven fabric composites has been observed in recent years. However, our understanding of their elastic and strength behaviour is still in its infancy. Modelling starts with the creation of a three-dimensional geometric model of the fabric structure. This analysis results in a logical and automated partition of the unit cell into a number of microcells, and the prediction of local fibre volume fractions and yam orientations. Through the application of a modified Fabric Geometry Model, the full set of elastic constants for the orthotropic material unit cell is obtained. A parametric study was performed to understand how the different geometric parameters of the fabric can be combined to determine the elastic behaviour of the composite material.