A razor strop or simply a strop (sometimes called a razor strap or strap) is a flexible strip of leather, canvas, denim fabric, balsa wood, or other soft material, used to straighten and polish the blade of a straight razor, a knife, or a woodworking tool such as a chisel. In many cases stropping re-aligns parts of the blade edge that have been bent out of alignment. In other cases, especially when abrasive polishing compound is used, stropping may remove a small amount of metal (functionally equivalent to lapping). Stropping can also burnish (i.e., push metal around on) the blade. [1]
The strop may be a hanging strop or a hand-held paddle. Various abrasive compounds may be applied to the strop to aid in polishing the blade while stropping to obtain a mirror-like finish. Common abrasive compounds include half-micron diamonds, green chromium(III) oxide, white rouge ( aluminum oxide), and jeweller's rouge ( iron(III) oxide).
Stropping is traditionally associated with straight razors used for shaving, as these are the thinnest blades in everyday use, and therefore require frequent stropping. Kitchen knives may be straightened on a honing steel if less sharpness is acceptable. In principle, any blade may be polished by stropping. Custom strops are made to hone irregularly-shaped tools, such as chisels or gouges, and nearly any piece of smooth leather or heavy fabric infused with abrasive compound may be used for stropping.