Razor. Coloured scanning electron micrograph of a disposable safety razor with hairs (brown) stuck to it. The two blades of the razor (white, at centre) are held in a blue mounting. The use of two blades allows a closer shave. Safety razors are so named because it is impossible to inflict a deep cut with them. They were invented by the American, King Camp Gillette, in 1871; the first twin-blade safety razor was introduced in 1971. Magnification: x4 at 5x7cm size. Magnification; x18 at 25cm x12cm size.