burin, engraving tool with a metal shaft that is cut or ground diagonally downward to form a diamond-shaped point at the tip. The angle of the point of a particular tool affects the width and depth of the engraved lines. The shaft of the tool is fixed in a flat handle that can be held close to the working surface; it has a wide rounded end for bracing against the palm of the hand. The point is guided by thumb and forefinger.