A strip for dental plastic retainers or plastic dental prosthesis consisting of at least 4 and at most 8 interconnected layers of endless threads which possess a yarn count of less than 1 tex; the strip possesses a thickness of maximum 500 .mu.m; the endless fibers of a layer (10) consist preferably of colorless glass fibers in which the cross linkage of the resin which beds-in the fibers is simplified by the effects of light. Preferably, each individual layer consists of a strip whose warp threads (11) and weft yarns (12) are combined to a woven strip in the form of a plain fabric weave bond.