a tube construction for providing releasably interlocking fastener strips to be attached to the surface of film for bags including an elongate thin plastic tube having a range of gauges from 0 . 0015 inch to 0 . 005 inch with at least six shaped plastic profiles projecting from the surface of the tube and integral therewith being formed by the same extrusion process with one - half of the number of profiles being female and the other half being male profiles , and the male and female profiles shaped and sized so as to be capable of releasably interlocking with each other and with the film between the profiles having a distance no greater than 2 inches , and said film being longitudinally severable between profiles to provide fastener strips for laminating onto the surface of a plastic film to be converted into reclosable plastic bags .