Razor be used on both sides, with two open edges. The blade on the double-edged safety razor is slightly curved to allow for a smoother and cleaner shave. In 1901, the American inventor King Camp Gillette, with the assistance of William Nickerson, patented a new variation of safety razor with disposable blades. Gillette realized that a profit could be made by selling an inexpensive razor with disposable blades. This has been called the razor and blades business model, and has become a very common practice for a wide variety of products. Many other brands of safety razors have come and gone.
Safety razor professional) and remained a barrier to the ubiquitous adopting of the "be your own barber" ideal. The first safety razors used a single-edge blade that was essentially a 4 cm long segment of a straight razor. A flat blade that could be used alternately with this "wedge" was first illustrated in a patent issued in 1878, serving as a close prototype for the single-edge blade in its present form. New single-edge razors were developed and used side-by-side with double-edge razors for decades. The largest manufacturers were the American Safety Razor Company with its "Ever-Ready" series, and the Gem Cutlery Company