Abstract: A tube of weldable sheeting for the production of carrier bags comprises first and second tube wall portions extending longitudinally of the tube in circumferentially spaced relationship. Alternating ribs and bands, extending longitudinally of the tube form together each of the first and second tube wall portions, each of the ribs being of lesser width and greater thickness than each of the bands. Third and fourth tube wall portions extending longitudinally of the tube are integrally connected to the first and second tube wall portions so as to form a tubular formation together with the first and second tube wall portions, the third and fourth tube wall portions having a thickness corresponding approximately to 1/4 of the sum total of the thicknesses of one of the ribs and one of the bands.