Look at whatever modern presswork nether a loupe as well as you'll come across those ubiquitous halftone dots. Even inkjet presses locomote dots to practise the terminal image.
However, at that spot is a printing procedure that eliminates halftone screening completely as well as renders truthful continuous note lithography.
On the left is a total ikon of a 12" x 18" reproduction of a Mondrian painting. On the right is a close-up of simply the centre of the image. No halftone dots!
Collotype (a.k.a. photo-gelatin, heliotype, albertype, litchdruck, phototypie process)
Collotype is a photographic method of producing a lithographic printing surface inwards gelatin inwards which tones tin live reproduced without the locomote of whatever halftone screen. This reproduction method was devised nigh 1860 past times a Mr. Poitevin as well as introduced commercially inwards 1867 nether the mention "phototypie" past times du Motay as well as Maréchal.
Although it initially became a widely used process, it was really hard to command as well as non suited for long press runs. As a result, it was replaced past times conventional outset lithography (with its halftone screening) as well as became a specialized procedure that was to a greater extent than oft than non used for fine fine art reproductions. Today, at that spot are exclusively a really few printers using this procedure (e.g. Black Box Collotype Ltd inwards the United States of America as well as Benrido inwards Japan).
Collotype printing
The collotype plate is made past times coating a plate of glass, or sometimes metal, alongside a substrate composed of gelatin or other colloid as well as hardening it. Then it is coated alongside a thick coat of bichromated gelatin as well as dried carefully at a controlled temperature (a trivial over 50° C waters) hence it 'reticulates' or breaks upwards into a finely grained designing when washed subsequently inwards roughly 16° C water. The plate is hence exposed inwards contact alongside the negative using an ultraviolet (UV) lite source which changes the mightiness of the exposed gelatine to subsequently absorb water. The plate is developed past times carefully washing out the bichromate tabular array salt as well as dried without heat. The plate is left inwards a cool dry out house to cure for 24 hours earlier using it to print.
Exposing the celluloid negative This sentiment is of the dorsum of the photographic television camera which is gear upwards at a right angle to the master copy art.
An artist/retoucher plant on the celluloid negative to brand adjustments to the tones of the negative hence that they volition practise a plate that accurately reproduces the master copy art. With a total coloring textile reproduction, all four, or more, negatives volition bring to live corrected.
The drinking glass plate beingness exposed.
A photo-electric jail cellular telephone is used to exam the note as well as coloring textile density.
To attain prints, the plate is dampened alongside a glycerine/water mixture which is slightly acidic , hence blotted earlier inking alongside Collotype ink using a leather or velvet roller. Influenza A virus subtype H5N1 hard finished newspaper such every bit Bristol, is hence set on overstep of the plate as well as covered alongside a tympan earlier beingness printed typically using a manual proof press.
Two views of a Collotype press.
The outcome is a reproduction that is indistinguishable from a photographic print.
Full ikon as well as magnified to present the detail.
Collotype printing at Benrido, Japan:
Steps demonstrated include; exposing the fine art to film, processing as well as inspecting the celluloid negative, retouching the negative, coating, drying as well as hence exposing the plate to the negative, washing the plate to take excess bichromate, wetting the plate as well as making the ikon score prior to inking, as well as hold out printing the job.
The closest modern equivalent to producing continuous note lithographic printing is 10 micron FM screening which, fifty-fifty nether 10x magnification, appears to non bring been halftone screened every bit inwards the representative below:
Canadian postage stamp stamps are an first-class representative of 10 micron FM screening that results inwards presswork alongside a like ikon fidelity to Collotype printing.
However, at that spot is a printing procedure that eliminates halftone screening completely as well as renders truthful continuous note lithography.
Collotype (a.k.a. photo-gelatin, heliotype, albertype, litchdruck, phototypie process)
Collotype is a photographic method of producing a lithographic printing surface inwards gelatin inwards which tones tin live reproduced without the locomote of whatever halftone screen. This reproduction method was devised nigh 1860 past times a Mr. Poitevin as well as introduced commercially inwards 1867 nether the mention "phototypie" past times du Motay as well as Maréchal.
Although it initially became a widely used process, it was really hard to command as well as non suited for long press runs. As a result, it was replaced past times conventional outset lithography (with its halftone screening) as well as became a specialized procedure that was to a greater extent than oft than non used for fine fine art reproductions. Today, at that spot are exclusively a really few printers using this procedure (e.g. Black Box Collotype Ltd inwards the United States of America as well as Benrido inwards Japan).
Collotype printing
The collotype plate is made past times coating a plate of glass, or sometimes metal, alongside a substrate composed of gelatin or other colloid as well as hardening it. Then it is coated alongside a thick coat of bichromated gelatin as well as dried carefully at a controlled temperature (a trivial over 50° C waters) hence it 'reticulates' or breaks upwards into a finely grained designing when washed subsequently inwards roughly 16° C water. The plate is hence exposed inwards contact alongside the negative using an ultraviolet (UV) lite source which changes the mightiness of the exposed gelatine to subsequently absorb water. The plate is developed past times carefully washing out the bichromate tabular array salt as well as dried without heat. The plate is left inwards a cool dry out house to cure for 24 hours earlier using it to print.
An artist/retoucher plant on the celluloid negative to brand adjustments to the tones of the negative hence that they volition practise a plate that accurately reproduces the master copy art. With a total coloring textile reproduction, all four, or more, negatives volition bring to live corrected.
The drinking glass plate beingness exposed.
A photo-electric jail cellular telephone is used to exam the note as well as coloring textile density.To attain prints, the plate is dampened alongside a glycerine/water mixture which is slightly acidic , hence blotted earlier inking alongside Collotype ink using a leather or velvet roller. Influenza A virus subtype H5N1 hard finished newspaper such every bit Bristol, is hence set on overstep of the plate as well as covered alongside a tympan earlier beingness printed typically using a manual proof press.
Two views of a Collotype press.The outcome is a reproduction that is indistinguishable from a photographic print.
Collotype printing at Benrido, Japan:
Steps demonstrated include; exposing the fine art to film, processing as well as inspecting the celluloid negative, retouching the negative, coating, drying as well as hence exposing the plate to the negative, washing the plate to take excess bichromate, wetting the plate as well as making the ikon score prior to inking, as well as hold out printing the job.
The closest modern equivalent to producing continuous note lithographic printing is 10 micron FM screening which, fifty-fifty nether 10x magnification, appears to non bring been halftone screened every bit inwards the representative below:
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