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.
A Blade in the Dark and neighbors are murdered by a razor-wielding slasher, and there is a weird next door neighbor who is a key suspect. Lamberto Bava was offered to direct "A Blade in the Dark" while he was assisting Dario Argento on "Tenebrae" (1982). The film was written by the husband and wife writing team of Dardano Sacchetti and Elisa Briganti. Bava and Sacchetti recalled that their collaboration was difficult, with the two being more friendly during the production of "Twitch of the Death Nerve" (1971), but their approach to this film was at odds with each other. The film was initially commissioned