These straight edges are specifically designed to allow safe cutting with a razor knife or rotary cutter. They feature a raised edge behind which fingers are safely recessed during use. They are extruded, tempered aluminium. Anodized colour with photo anodized measurement markings and neoprene backing to prevent slipping make this a durable and efficient tool for drafting, card and book making and many other purposes. Also works well as an inking edge; measure and ink or cut without having to change tools.