Woven materials, like Dacron, may be specified as either high or low "tenacity", as indicated, in part by their denier count (a unit of measure for the linear mass density of fibers). High-tenacity Dacron comes in multiples of 220, 350 and 570 deniers, whereas low-tenacity Dacron comes in multiples of 150, 250, and 400 deniers. Sailcloth is typically heat-shrunk to tighten the weave and then receives a chemical bonding finish of melamine. Such cloth is typically specified by deniers for warp and fill (weft), e.g. 220/570.