Typewriter the first major typewriter with these features. However, older "nonvisible" models continued in production to as late as 1915. A significant innovation was the shift key, introduced with the Remington No. 2 in 1878. This key physically "shifted" either the basket of typebars, in which case the typewriter is described as "basket shift", or the paper-holding carriage, in which case the typewriter is described as "carriage shift". Either mechanism caused a different portion of the typebar to come in contact with the ribbon/platen. The result is that each typebar could type two different characters, cutting the number of keys and
Particle Transfer Roller passes in contact with it. The rollers themselves are then cleaned, usually in soapy water, and dried before the next use. Particle Transfer Roller The Particle Transfer Roller, often abbreviated to PTR, is a device for cleaning motion picture film. It consists of a cylindrical roller coated with urethane, over which the surface of the film passes. The Particle Transfer Roller was developed by Eastman Kodak and launched in 1989. It was intended to replace the organic solvents that were the main method of film cleaning before that point. Although their effectiveness is not usually considered sufficient for lab operations,