Canvas stretcher keys are used to tighten loose or sagging canvas by expanding the corners of stretcher bar frames. Simply insert the wedges into the slots at the corners of the frame and gently tap them to increase canvas tension. These wood stretcher keys feature a precision tapered design that allows gradual tightening without damaging the frame. They are compatible with most standard canvas stretcher bars used by artists and framers. Available in multiple pack sizes, these canvas wedges are ideal for artists, studios, galleries, and canvas restoration.