A seat and/or backrest part of folding furniture, especially garden or camping furniture, comprising a frame and a cover which may be anchored to this frame. The frame includes two hollow sections which are arranged at a distance from one another determining the width or length of the seat or backrest surface and are open on at least one face and with a longitudinal slot, in such a way that the cover may be led into and through the open face of the hollow sections and their longitudinal slot. The edges of the cover are held inside the hollow sections by edge strips formed on same. The edge strips may be displaced inside the hollow sections in a direction perpendicular to their longitudinal extension with corresponding tensioning of the cover.