Abstract: A jig for use in stitching together two layers of material on a stitching line defining a corner. The jig has a lower plate (1) having a slot (4) through which stitching may be effected, the slot including at least one corner. An upper plate cooperates with the lower plate and a fulling plate (3) is positioned between the lower and upper plates and has fulling means (6 to 8) on its upper surface for defining pleats in a fabric layer placed over the fulling means. At least one of the fulling means has an upstanding, pleat-forming member (11) which is positioned so that the pleat formed thereby extends towards the slot (4) at a line that intersects the slot at a location lying ahead of the associated corner (13).