Screenless lithography
Encyclopedia
Screenless lithography is a reprographic technique for halftoning dating to 1855, when the French chemist and civil engineer Alphonse Poitevin
discovered the light–sensitive properties of bichromated gelatin and invented both the photolithography
and collotype
processes. After the invention of the halftone screen in the 1880s, screenless lithography was abandoned. Until the end of World War II, two kinds of photomechanically made plates were used in lithography: albumin plates and deep-etch plates. Presensitized plates appeared in the 1950s, and wipe–on plates appeared in the 1960s.
By the mid-1960s research on screenless lithography had successfully developed in Europe to the stage where continuous-tone plates could be manufactured for use with positive film images. Researchers discovered that under certain conditions the combination of fine plate grain and the newly developed plate coatings produced a plate capable of holding nearly all of the tones from a continuous-tone positive. Commercial use of this plate has not flourished; today it is still in limited use, primarily because the continuous–tone printing plate technology is expensive and necessitates stringent quality control.
Since the late 1960s artists and printers have been experimenting with these new plates, using photomechanical film and handmade positives made from thin translucent or transparent plastic sheets and a variety of drawing and painting materials. Screenless lithography has been incorrectly referred to as diazo plate lithography and Mylar
lithography.
Alphonse Poitevin
Alphonse Poitevin was a French chemist, photographer and civil engineer who discovered the light–sensitive properties of bichromated gelatin and invented both the photolithography and collotype processes....
discovered the light–sensitive properties of bichromated gelatin and invented both the photolithography
Photolithography
Photolithography is a process used in microfabrication to selectively remove parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate...
and collotype
Collotype
Collotype is a dichromate-based photographic process invented by Alphonse Poitevin in 1856. and was used for large volume mechanical printing before the existence of cheaper offset lithography. It can produce results difficult to distinguish from metal-based photographic prints because of its...
processes. After the invention of the halftone screen in the 1880s, screenless lithography was abandoned. Until the end of World War II, two kinds of photomechanically made plates were used in lithography: albumin plates and deep-etch plates. Presensitized plates appeared in the 1950s, and wipe–on plates appeared in the 1960s.
By the mid-1960s research on screenless lithography had successfully developed in Europe to the stage where continuous-tone plates could be manufactured for use with positive film images. Researchers discovered that under certain conditions the combination of fine plate grain and the newly developed plate coatings produced a plate capable of holding nearly all of the tones from a continuous-tone positive. Commercial use of this plate has not flourished; today it is still in limited use, primarily because the continuous–tone printing plate technology is expensive and necessitates stringent quality control.
Since the late 1960s artists and printers have been experimenting with these new plates, using photomechanical film and handmade positives made from thin translucent or transparent plastic sheets and a variety of drawing and painting materials. Screenless lithography has been incorrectly referred to as diazo plate lithography and Mylar
PET film (biaxially oriented)
BoPET is a polyester film made from stretched polyethylene terephthalate and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties and electrical insulation.A variety of companies manufacture boPET and other...
lithography.