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 After their introduction in 1680, straight razors became the principal method of manual shaving for more than two hundred years, and remained in common use until the mid-20th century. Straight razor production eventually fell behind that of the safety razor, which was introduced in the late 19th century, and featured a disposable blade. Electric razors have also reduced the market share of the straight razors, especially since the 1950s. Since 2012, production of straight razors has increased multifold. Straight razor sales are increasing globally and manufacturers have difficulty satisfying demand. Sales started increasing since the product was featured in the