|
A photolith film〔(Photolith dictionary definition )〕 is a transparent film, made with some sort of tranparent plastic (formerly made of acetate). Nowadays, with the use of laser printers and computers, the photolith film can be based on polyester, vegetable paper or laser film paper. It is mainly used in all photolithography processes. A color image, or polychromatic, is divided into four basic colors: cyan, the magenta, the yellow and black (the so-called system CMYK (short name from ''cyan'', '' magenta '', '' yellow '' and '' black ''), generating four photolith film images, a photo filtered with each of the three basic colors plus a B&W film (addition of the three). For black-and-white images, such as text or simple logos, only one photolith film is needed. The ''photolith film'' it is sometimes recorded by an optical laser process on an ''imagesetter'' machine, coming from a digital file, or by a photographic process in a contact copier, if a physical copy of the original already exist. In the old offset printing plates acquire text or images to be printed after being sensitized from a photolith film. The photolith films, as well as vegetable and the ''laser'' films, are used to store plates, screens or other media sensitive to light as a backup for repeating their processes in the future. They normally store the information of the three or four separated colours on monochrome photolith films. ==See also== * Azo compound * Contact copier * Ozalid process * Diazo copier 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Photolith film」の詳細全文を読む スポンサード リンク
|