Nb frame is an innovative aluminum stretcher bar system for professional artists, museums and restorers. Its patented design creates a perfect framework for canvas stretching, free from deformation, twist and warp caused by humidity or dryness. The nb frame system is available in cut lengths and 3 metre profile lengths with separate assembly parts, and as pre-assembled frames in various sizes with back stapled 450 g/m2 linen, all in frame depths of 25 and 45 mm.