Safety razor the second blade cuts it further. The extent to which this is of practical consequence has, however, been questioned. Gillette introduced the first triple-blade cartridge razor, the Mach3, in 1998, and later upgraded the Sensor cartridge to the Sensor3 by adding a third blade. Schick/Wilkinson responded to the Mach3 with the Quattro, the first four-blade cartridge razor. These innovations are marketed with the message that they help consumers achieve the best shave as easily as possible. Another impetus for the sale of multiple-blade cartridges is that they have high profit margins. With manufacturers frequently updating their shaving systems, consumers can
Safety razor greatly extend their life. Disposable safety razors can be sharpened using various methods. There are commercial devices intended for this duty (Razormate, RazorPit, Blade Buddy, etc.). Myths claim that it is possible to sharpen a disposable razor by utilizing a pyramid but this is pseudoscience. Double-edge (DE) safety razors remain a popular alternative to proprietary cartridge razors, and usually offer significantly lower total cost of ownership since they are not marketed under the "razor and blades business model". DE razors are still designed and produced in many countries. Better known manufacturers include Edwin Jagger, Feather, iKon, Lord, Merkur, Mühle, Parker,