This is a patent application for an X stitching method, specifically intended for the assembly of uppers by the system known as tied string—stringlaster, with particular application in the footwear segment. The invention includes application to an upper (1), for full assembly of shoes, using string traction (2) as the responsible element for closing the edges of this upper (1), against the mold (3); with the overlock type stitching hereby used as an example of realization.