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 steel blades remain in limited production for lower income markets. Because Gillette held a patent on stainless blades but had not acted on it, the company was accused of exploiting customers by forcing them to buy the rust-prone blade. The risk of injury from handling razor blades was further reduced in 1970 when Wilkinson released its "Bonded Shaving System", which embedded a single blade in a disposable polymer plastic cartridge. A flurry of competing models soon followed with everything from one to six blades, with many cartridge blade razors also having disposable handles. Cartridge blade razors are sometimes considered to