Collotype:
The collotype process was used by numerous postcard printers at the turn-of-the-century, particularly for their monotone black orders. Some of the publishers of Hamilton postcards who ordered collotype cards were: B.C. Printing and Litho. Ltd., Vancouver; Cloke & Sons, Publishers, Hamilton; The International Stationery Co., Picton; and Stanley Mills & Co., Hamilton. The collotype process is described in A Guide to Early Photographic Processes as follows:
Collotype Printing (early 1870's to date)
A photomechanical printing process in which a metal or glass plate, coated with bichromated gelatin, was exposed under a negative. When the moistened gelatin dried, it reticulated, forming a fine-grained mesh-like structure on the surface, which took up greasy ink in proportion to the hardening produced by exposure. The ink was then transferred from the plate to paper, in a press. A number of processes based on this principle were in use, and is still operated for short run quality printing. Collotype prints show a well-defined, very characteristic irregular grain pattern when magnified.
Gelatine:
The gelatine process, used almost exclusively by the Photogelatine Engraving Co. Ltd. of Ottawa, was similar to the bromoil bromide process used in photography. A Guide to Early Photographic Processes describes this process as follows:
Bromoil Prints (1907 to 1940's)
Developed by C. Welbourne Piper from an idea by E.J. Wall, it was a variant of the oil-pigment process. Prints, or more usually, enlargements were made on a suitable gelatin-silver bromide paper, and the image was bleached in a solution containing potassium bicarbonate. The gelatin became selectively hardened so that it would take up more or less pigment when hand applied with special brushes. The bleached image was thus redeveloped in pigment, the distribution of which was to a large extent under the photographer’s control. Bromoil prints, which may be in a variety of colours, generally show broader tonal effects and more diffuse detail than conventional prints.
Half-Tone Engraving:
Half-tone is a class of photo-engraving in which the relief lines are produced by etching a plate that has received the photographic picture through a fine-ruled glass screen having from 55 to 200 lines to the inch. The closer the lines, the softer the tone, and the more difficult to print acceptably. For postcards half-tones are made on copper. The effect of the screen is to break the rays of light into tiny separate beams on the negative. If a half-tone illustration is observed closely, it will be seen that the shades and tones are not solid masses, but are tiny squares, or dots. Photo-engraved postcards are by far the most numerous type found. Modern chromes until quite recently, were printed using this process. A sampling of postcard publishers who, almost exclusively, ordered this type of postcard are: Jack H. Bain, Toronto; F.H. Leslie, Limited, Niagara Falls; Ontario Engraving Co., Hamilton; The Post Card & Greeting Card Co., Toronto and Valentine and Sons’ Publishing Co., Montreal and Toronto.
Letterpress:
Letters and words printed on paper or other materials. This term is frequently used to distinguish the printing of type from lithography, steel or copper-plate printing.
Line Engraving:
Line engraving is a class of photo-engraving in which a photograph is made of the drawing, or print, that is to be reproduced. The design is then printed from the photographic film on a prepared zinc plate. The portions of the face of this plate that are to remain high enough to be inked are treated chemically, so that the acid will not attack them. The plate is then put in an acid bath, and the acid eats down the unprotected metal. After the acid has done its work, various parts of the plate are cut or routed deeper by machinery, if necessary. Many of the advertising postcards printed on official postal stationery are of the line engraving type.
KEYWORD SEARCH TERM: line-engraved.
Photochrome:
The photochrome printing process was used almost exclusively by the Detroit Photographic Company, Detroit. This process had been developed in Switzerland and the firm secured exclusive ownership and rights in the United States to the patented process in 1897. Using an asphaltum process, the pictures were printed from finely grained lithographic stones with an asphalt coating. Continuous tone negatives were used exclusively, with no half-tone screen. Nine or ten colours were used, which gave the fine colour values.
Photo-Engraved:
For the purposes of the database descriptions on this website, the term photo-engraved has been used to describe postcards printed by the half-tone engraving process.
Photographic:
In 1902, the Eastman Kodak Company took advantage of the booming international postcard fad by issuing a postcard-size photographic paper on which images could be hand-printed directly from negatives. Gaslight photographic paper, the kind most commonly used for postcards, was so simple to process that energetic, determined amateurs or small entrepreneurs could make their own prints. Unlike the printing papers of the nineteenth century, which had required exposure in full sunlight, the gaslight papers were sensitive enough to be printed at night using artificial light - hence the name. The most popular brands seen with Hamilton subjects were the Canadian Kodak Company’s Ckc, Eastman Kodak Company’s Velox and Azo, and Ansco Company’s Cyko and Noko papers. See Real Photo Postcard Terms for more details on the various types of photographic paper used for postcards.
By about 1908, a mechanized process was developed for the manufacture of real photographic postcards. The process involved two machines, an exposing machine and a developing, fixing, toning and washing plant. The postcards emerged from the developing and toning plant, “yard after yard of pictures, in one continuous length, address side neatly printed all ready for hanging up to dry, and nothing further to be done than cutting them up”. Ellis Graber’s Photographic Machine Works, Tunbridge Wells, Kent (England) supplied the machines for S.J. Hayward, Montreal, and Byron Harmon, Banff (Alberta). It is likely that the Canadian Post Card Co. Ltd., Toronto, which produced a number of Hamilton postcards, made use of such machines.
KEYWORD SEARCH TERM: real photo.
Three-Colour Process:
From 1900 on, the three-colour process of colouring monotone black postcards was rapidly introduced worldwide. The colours used were yellow, red and blue in that order, followed by the picture outline in black. One printing block was used for each colour and used successively. If the blocks were not identical and superimposed exactly the colours would not print or register properly, producing blurred images.
