Safety razor the rectangular dimensions shared by the wedge, standard single-edge, and double-edge blades. The injector, itself, was also the first device intended to reduce the risk of injury from handling blades. The Gillette blade dispenser released in 1947 had the same purpose. The narrow injector blade, as well as the form of the injector razor, also strongly influenced the corresponding details of the subsequently developed cartridge razors. Both injector blades and injector safety razors are still available on the market, from antique stock as well as modern manufacture. The injector blades have also inspired a variety of specialised blades for professional
Straight razor more feedback on the resistance the blade meets while cutting the hair, which is an indicator of blade sharpness. Hollow-ground blades are preferred by most barbers and some high-end razor manufacturers limit their production exclusively to hollow ground razors. The third and final category refers to blade width. The width of the blade is defined as the distance between the back of the blade and the cutting edge. It is expressed in units of eighth of an inch. The sizes vary from up to , rarely . A wider blade can carry more lather, much like a scoop, during multiple