in the late 18th century, french engineer jean-jacques perret invented the safety razor. with this system, the skin is protected, from all but the edge of the blade. this makes cutting much harder. the first such razor was released in 1875 by the campfe brothers. in 1901, king camp gillette invented the first razor with disposable razor blades. the blades were thrown away after several uses. the number of times a disposable blade can be used depends on beard coarseness and shaving technique, but the average is about one week. the company, gilette still makes such razors today. they sell the razor relatively cheaply, and make big profits on the razor blades.