Abstract: In a method of making a window covering material a plurality of slats preferably made of fabric or plastic film, are provided. Each slat has opposite longitudinal edges and each longitudinal edge has a pocket with at least one transverse slot. There is one rail for each transverse slot in any selected slat. Each rail has a loop extending from the rail which loop is sized to fit within a selected transverse slot in a slat pocket. The fabric slats and the rails are positioned so that there is one loop in each transverse slot. Then a rod is inserted into each pocket of the fabric slat so that for each pocket the rod passes through the loop in each transverse slot of that pocket. If desired, one may attach a light screening flap to one or both longitudinal edges of the slats.