Fray stop is a colourless liquid that prevents stressed areas; such as button holes, seams, shirt collars, and cuffs; from fraying by reinforcing the fibres. When sewing the edges of curves, Fray Check can be applied to the edge of the curves, which are then conveniently cut before turning and without fraying. This sealing solution gives rolled seams a stable finish. It can even be used to provide a fray-free seal to the edges of self-cut fabric motifs. This treatment can be repeated as often as desired. You can check out Prym's Youtube page for an instructional video.