Shape matrices have been used as a representation of planar shapes like industrial parts or printed characters. In this paper, we investigate the use of shape matrices as a mixed shape factor for off-line signature verification. By mixed shape factor we mean any global shape factor where the position of local measurements are take into account in the definition of a similarity measure between two representations. It was demonstrated that using a good similarity measure between two shape matrices, this shape factor is relatively well suited for the global interpretation of signature images.