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 carries the lather on it during multiple shaving strokes, while the multi-blade razors are not nearly as efficient at such a task because of their considerably smaller blade geometry. Straight razors are also much easier to clean and can handle tougher shaving tasks, such as longer facial hair, than modern multi-blade razors, which tend to trap shaving debris between their tightly packed blades and are easily clogged, even with relatively short stubble. In addition, multi-edge razors can irritate the skin due to their multi-blade action, and this can lead to a condition known as pseudofolliculitis barbae, colloquially known as "razor