Abstract: A stack (2) of individual, pre-formed bags, each bag (4) comprising: a body portion (6) formed by front (8) and rear (10) walls having closed sides (12), a closed bottom (13) and an open mouth (14); first and second side handles (16, 18) extending away from the body portion (6) at opposite sides of the open mouth (14); and a block header (20) separably connected to the first and second side handles (16, 18), wherein the block header (20) is provided with at least one internal line of weakness (26, 28) such that it may be divided into individual attachment tabs (40, 41, 42), each attachment tab being provided with a support member receiving aperture (43, 44, 45) for receiving a support member of a bag dispenser.