Abstract: A method for manufacturing a sack or bag with a bottom being rectangular in the filled state and a handle portion joined thereto. An economical method for production by machine, according to the invention includes the following steps carried out sequently. A flattened tube piece (10) is provided with two slits at one end. The slits are substantially parallel to each other and to the lateral edges of the tube. Then a bottom square is formed by folding the tube piece near the slit end with corner tucks (14) and side tucks (16, 18). A prefabricated handle portion (22), including a reinforcing strip (24) and a connection strip (26) is glued or welded such that an edge portion (20) of one side tuck (16) is not covered by the prefabricated handle portion. Subsequently, such side tuck (16) and the corner tucks (14) are folded along a fold line (28) extending through the center of the corner tucks (14) and the uncovered edge portion (20) is glued or welded to the corresponding adjacent section of the handle portion.