File:Horgan's half-tone and photomechanical processes (1913) (14777277501).jpg

Identifier: horganshalftonep00horg (find matches)
Title: Horgan's half-tone and photomechanical processes ..
Year: 1913 (1910s)
Authors: Horgan, Stephen Henry, 1854-1941
Subjects: Photomechanical processes
Publisher: Chicago: Inland Printer Co
Contributing Library: Getty Research Institute
Digitizing Sponsor: Getty Research Institute

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iron is deposited is difficultto keep in condition when used but seldom. The outfit for steel deposition consists of a depositingtank with its solution, an iron plate for an anode and asmall dynamo or batteries. It is better to consult a dealerin electrotyping supplies for advice as to the batteries ordynamo, who will be guided by the size of the plates andthe number of them. One of the simplest of the iron depositing solutions isthe one recommended by Mr. Thomas Huson and is asfollows: Water 40 ounces Chlorid of ammonium 2 ounces Double sulphate of iron and ammonia 1 ounce Protosulphate of iron 1 ounce The salts are to be dissolved in the water and the solu-tion filtered just before use. The important feature ofthis work is to get the surface of the copper absolutelyclean with whiting and water in order that the iron filmwill be evenly deposited. The deposition should not takemore than fifteen minutes, and to keep the steel facingfrom rust it must be kept covered with oil or beeswax.
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SWELLED GELATIN ENGRAVING.Moss Engraving Company, about 1883. THE MOSS PROCESS, KNOWN AS THE SWELLED GELATIN RELIEF PROCESS, THE FIRSTPRACTICAL PHOTO-RELIEF PROCESS. It was in 1871-72 that John Moss worked out in NewYork the first practical photoengraving process. He per-formed certain portions of the process in secret and sup-posed that his secrets died with him. His methods havenever been published, but as the writer was experimentingon similar lines ten years later, and obtained good resultseventually, it is safe to assume that the Moss process wasabout as follows: A gelatin solution was made up daily in the followingproportions: Coxs gelatin 1 ounce Water 12 ounces Bichromate of potash 120 grains The gelatin is allowed to swell in the water and is thenheated to 1200 F., when the gelatin dissolves and thebichromate, in a finely powdered form, is stirred in. Thesolution is kept at this temperature until it is filtered andthen poured on leveled pieces of plate glass which have hadthe

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