In a method for closing a tubular sack body made from a woven fabric of monoaxially drawn polymer, in particular polyolefin or polypropylene, ribbons, comprising the production of a bottom fold in such a way that the sack has a substantially rectangular bottom, at least two layers of the bottom which overlap one another at least partially are welded to one another in the region of their overlap by way of at least one welded seam in order to close the bottom, wherein the at least one welded seam extends at least over the length of the broad side and/or the narrow side of the rectangular bottom.