An apparatus to aid in the making of a light filtering window shade from shade fabric comprised of a series of longitudinal vane members having their longitudinal edges respectively secured to front and rear fabric panels. The apparatus comprises an assembly table and a roller tube positioning rail. The table has first and second ends with the first end adapted to facilitate the cutting of the shade fabric to a desired length. The roller tube positioning rail is releasably securable to the assembly table and releasably receives a roller tube having one end of the shade fabric secured thereto. The positioning rail permits the roller tube, and the shade fabric secured thereto, to be set-off a predetermined distance from the first end of the assembly table. The positioning rail maintains the roller tube generally parallel to the first end of the assembly table.