Sack cloth: most of them are double warp plain weave, and there are also double warp twill weave. The warp yarn is generally about 3 metric yarns, and the weft yarn is about 1.5 metric yarns. After woven, the gunny bag cloth shall be cut according to the specification and sewing method of the gunny bag, and then be sewn with the roll sewing method or double loop interlocking method. There are three sewing methods for gunny bags: sewing both sides to make the bottom of the bag seamless; Or seam one side and bottom to make the other side seamless; Or single seam bottom makes both sides seamless (applicable to fabrics on circular looms). The opening of the gunny bag must be rolled and folded.