Abstract: A mounting for a sheet that has a bead about its periphery includes frame members forming a rectangle with each frame member including mutually parallel multiple engagement surfaces defined on ribs. An elongate retainer includes an elongate flange with an interlocking surface which can selectively interlock with any one of the engagement surfaces on the frame. The frame also has a frame rail having a rail surface that faces away from a retainer rail surface on a rail of the retainer. A tool including pinch rollers squeeze the rail surfaces toward one another to place the sheet material held by the retainer in tension while the interlocking surface is engaged with the appropriate engagement surface.

Abstract: A mounting for a sheet that has a bead about its periphery includes frame members forming a rectangle with each frame member including mutually parallel multiple engagement surfaces defined on ribs. An elongate retainer includes an elongate flange with an interlocking surface which can selectively interlock with any one of the engagement surfaces on the frame. The frame also has a frame rail having a rail surface that faces away from a retainer rail surface on a rail of the retainer. A tool including pinch rollers squeeze the rail surfaces toward one another to place the sheet material held by the retainer in tension while the interlocking surface is engaged with the appropriate engagement surface.