Printing Techniques, several different ways in which printing may be accomplished, such as lithography, letterpress, flexography, gravure, and screen printing. All of these printing techniques use simple mechanisms for rapidly applying colorants to substrates such as paper or plastic to form multiple reproductions of original images for mass distribution.
Multiple colors can be printed in one pass through the press. Spot color printing uses custom mixed inks to reproduce specific colors and is widely used in package printing, where large areas of uniform color are common. Process color printing uses four transparent inks—cyan (blue-green), magenta (red), yellow, and black—printed one on top of another in varying amounts. Color photographs and other artwork can be faithfully reproduced by this method.
Most modern printing presses transfer ink from a cylindrical printing surface to moving sheets or rolls of substrate. Presses that print on rolls, or webs, can achieve speeds of 600-900 m (2000-3000 ft) per minute. Presses that print on sheets are generally slower than web presses but can print on thicker substrates, such as bristol board and sheet metal.
Since the 1960s, advancements in photography and electronics have had a profound effect on the manufacture of printing surfaces. Light-sensitive materials such as diazonium resins and photopolymers make it possible to produce durable printing surfaces photographically rather than mechanically. Computer-based systems allow the rapid production of the films used to transfer images to printing surfaces. Some printing surfaces can even be prepared directly by machines employing computer-controlled laser beams or diamond styluses. Images generated on computer systems and stored in databases can now be transferred directly to printing surfaces without any intermediate steps. Taken as a whole, these changes have been called the prepress revolution.
Multiple colors can be printed in one pass through the press. Spot color printing uses custom mixed inks to reproduce specific colors and is widely used in package printing, where large areas of uniform color are common. Process color printing uses four transparent inks—cyan (blue-green), magenta (red), yellow, and black—printed one on top of another in varying amounts. Color photographs and other artwork can be faithfully reproduced by this method.
Most modern printing presses transfer ink from a cylindrical printing surface to moving sheets or rolls of substrate. Presses that print on rolls, or webs, can achieve speeds of 600-900 m (2000-3000 ft) per minute. Presses that print on sheets are generally slower than web presses but can print on thicker substrates, such as bristol board and sheet metal.
Since the 1960s, advancements in photography and electronics have had a profound effect on the manufacture of printing surfaces. Light-sensitive materials such as diazonium resins and photopolymers make it possible to produce durable printing surfaces photographically rather than mechanically. Computer-based systems allow the rapid production of the films used to transfer images to printing surfaces. Some printing surfaces can even be prepared directly by machines employing computer-controlled laser beams or diamond styluses. Images generated on computer systems and stored in databases can now be transferred directly to printing surfaces without any intermediate steps. Taken as a whole, these changes have been called the prepress revolution.
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