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.
Straight razor straighten the microscopic sharp edge, one must strop the blade on leather periodically. To sharpen or finish the blade using a suspended strop, the razor is pushed toward the suspension ring while both the back and the cutting edge lie flat on the strop and with the back of the blade. No pressure should be applied on the cutting edge. A strop may be two sided with leather on one side and cloth on the other side. The cloth is used for blade alignment and sharpening. The leather is for finishing. The stropping process involves sliding the razor blade flat