A female loop portion for a hook and loop self-adhesive, comprising a film (1) made of at least one thermoplastic and a plurality of filaments (2) which are separate from one another and attached to one of the surfaces of the film, each filament comprising a series of fastening sections (15) and a series of loop sections (4) alternating with the fastening sections, the filaments being attached to the film along the fastening sections while the loop sections are at a distance from the film so as to form loops, and characterized in that a cross-sectional area of one loop section of a filament is less than a cross-sectional area of one fastening section of said one filament.