METROPOLITAN POSTCARD CLUB OF NEW YORK CITY GUIDE TO PRINTING TECHNIQUES 5
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Photography and the Black Arts - part three


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Introduction
1. Traditional pt.1
2. Traditional pt.2
3. Black Arts pt.1
4. Black Arts pt.2
6. Halftone pt.1
7. Halftone pt.2
8. Tricolor pt.1
9. Tricolor pt.2
10. Novelties
11. Digital
12. Facsimiles

GRAVURE

In general usage the term gravure is often applied to any photo-intaglio technique but it specifically makes reference to prints of fine grain made through the photogravure or rotogravure process. Gravure is an old technique and it could be argued that the very first photographs in the form of heliographs were actually gravures. The gravure process has continued to evolve since its inception and is still widely used in commercial printing today. It was used in the production of many postcards but it was a pricey technique that limited its application. Most higher end monochrome postcards printed in Europe between the two world wars were produced through gravure.

Photoglyphic Engraving
In the 1820’s the printer Nicephore Niepce turned the paper of an engraving translucent by saturating it with wax so that he could expose it like a negative to a copper plate made light sensitive with a coating of bitumen. The result was the heliograph, the first known permanent photomechanical transfer but the various problems that continued to be encountered always prohibited its commercial use. His experiments however caught the eye of the painter Louis Daguerre and they formed a partnership to carry this technique further. Niepce’s death in 1833 cut this collaboration short, and it took four more years for Daguerre to invent the daguerreotype. He planed to keep this process a secret but just two years later he was forced to sell it to the French government out of desperation after his studio burnt down. The process began by photosensitizing a silver plate with iodide of silver, and immediately after exposure to light it would be passed over vapor from a hot bath of mercury. The mercury would only adhere to the iodide of silver in relation to where it received the most light, and the remaining emulsion was washed away in a bath of salt water. The resulting low relief caused minute shadows when light fell across it at an angle, and this replicated the appearance of the scene shot through the camera’s lens. While many improvements were made to this process, daguerreotypes still only produced a one of a kind image that mirrored the original subject and its surface was so delicate it could not be touched. Its use ended in the 1860’s while in competition with photography but its implications would live on.

W.H. Fox Talbot continued the Experiments that Thomas Wedgewood made in 1802 in which he captured an image on photosensitized paper; but 1935 it was Talbot who finally found a way to permanently fix this transfered image so it would not fade away. While this marked the beginning of true photography, Talbot also sought out ways to utilize photography in printing. By 1852 he began experimenting with gelatin emulsions (fish glue) for their potential use as an acid resist in etching photographic images onto metal plates. Six years later he realized he could achieve richer tones by first coating the polished metal substrate with a dusting of gum copal powder, which was melted onto the plate before sensitizing it with gelatin. The copal also acted as an acid resist but with a delicate irregular grain. It also guarantied that a fine texture would be bitten into the plate even if too much of the emulsion was washed off.




PHOTOGRAVURE (Hand Gravure)

Printers had seen potential in daguerreotypes and by the 1840’s some were being etched and engraved upon to strengthen the image for printing, gut the plate’s surface remained delicate and this method had limited use. Eventually the photoglyphic engraving process as used by Talbot evolved into photogravure (called heliogravure in Europe) by substituting the same fine resin powder as used in aquatint for the copal. Once the rosin has melted to a plate’s surface to create a random dot pattern, a clear photosensitive dichromate gelatin emulsion is applied. When dry it is then exposed to a positive transparency where the gelatin light hardened areas form an additional acid resist. The remaining gelatin is wash away in proportion to the density of the transparency that covered it, either nearly or completely exposing the metal surface of the plate. The plate is then heated at a higher temperature making its surface very hard, and the remaining resist is sometimes dyed a dark hue to better observe the image against the exposed metal. When placed in successive acid baths of decreasing strength, the metal will first dissolve in the exposed areas between the rosin dots. The thinner areas of gelatin will eventually wear away in proportion to their exposure to light and reveal more bare metal of the plate underneath. Because these areas have less contact time with the acid they will not etch as deeply, and these shallow wells will hold less ink producing lighter tones when printed.

Photogravure produces thousands of irregular ink cells in varying depths that can merge into a subtle continuous toned image with very rich blacks. In addition the printing plate is also very durable, able to yield sixty thousand impressions. Though the results obtained by this process are of a higher quality than many other printing methods, its complexity makes it relatively more expensive and others sought ways of reducing cost. The Jaffe Brothers in Vienna expanded upon Talbot’s photographic veil in 1877 using millers gauze to break up the image while being photomechanically transferred. Other techniques such as the stagmatype (spitzertype) introduced in 1866 featured a gum grain with the photosensitive gelatin emulsion. All of the alternatives faired worse in the marketplace, so despite the cost of photogravure this process continued to be used even after the introduction of rotogravure and up into the 1930’s but only to produce higher end postcards. Only a handful of fine printers use this process today.

Postcard

Photogravure: The tonalities of photogravure on this early postcard appear almost continuous and unbroken even under high magnification and are often difficult to identify. Only occasional small white dots from the underlying aquatint may be visible as seen in the detail below.

Postcard Detail

The printing plates used with photogravure and collotype both hold ink in the spaces formed between particles of resist that leave their own distinctive patterns on the final print. They show up as white dots on photogravure from where the grains of aquatint once sat on the plate preventing it from biting in the acid bath. The small white marks on collotypes tend to be wormy in appearance as they are the result of the light hardened reticulated gelatin emulsion. A further distinction between these to processes is in their tonal structure. On close examination the ink in photogravure sits as a crust atop a paper’s surface creating rich flat blacks while the thiner ink film of a collotype produces a good range of grey but poor dark tones. While these are the major differences to look for in making a determination of technique there is a problem, they do not always hold true. Many different patterns can be created with aquatint. If the rosin crystals are heated too long or over too high a heat they can melt into each other. This can result in chain like patterns that are wormy similar to curdled gelatin. The various practitioners of collotype had many trade secrets that often rendered the texture of one different from another. Sometimes the white marks produced are so small they have no distinctive shape at all and cannot be differentiated from a fine aquatint. Some of these printers also managed to push the collotype process into producing real blacks while the dark crust of photogravure will not appear on printed material of light subject matter.

Postcard

Photogravure: Photogravure’s tendency to render soft tones works against it on this postcard. The atmosphere of this distant landscape provides little contrast and few details to pick up on and the image rendered looses coherence. This effect is further exaggerated by the soft uncoated paper it is printed on.

Duogravure
Duogravures were produced by similar procedures to those used in the lithographic duograph process except that these images were etched as gravure into a metal plate. Two separate processing transparencies are made from the same photograph with one exposed to capture medium to light tones, the other darker values. When printed together from one plate inked in a light neutral color and another in a darker color they produced a much richer looking image than could be achieved from black & white alone. This process became very popular in the 1930’s for the fine reproduction of photographs, but it was mostly used on European postcards.

Postcard

Duogravure: At first glance this postcard in photogravure appears to be printed in a deep brown. The detail below reveals that a lighter brown has been printed under the black to carry the lighter values.

Postcard

Color Photogravure
As with all intaglio techniques photogravures could be printed in color by employing multiple plates, one for each individual color that was desired. The color plates were often lightly etched so that no one color would overwhelm another when these opaque inks were united into a single print. Completely solid color fields were rarely printed as all areas were usually made up of a multitude of countless little markings. A tri-color intaglio printing method employing mezzotint had been patented by the German printer, Jakob Chrisoffel Le Blon in 1717 but it did perform well as a commercial endeavor. It was revised in the form of color gravure in the 1880’s but registration problems added to its general difficulty and its high cost limited commercial production.


Crayon Gravure
Crayon gravure is not a printing technique but a style. It reproduces the texture of crayon, which in most cases is synonymous for pastel, which is printed through color photogravure. A very coarse grain is often employed when making the photomechanical transfer of the illustration onto a printing plate. This further enhances the illusion of a drawing on rough paper as the white dots have a similar appearance to the recessed areas of the paper’s surface that do not pick up pigment when drawing. This was never widely used in the printing trades, probably due to cost, but it can be found on postcards well into the 20th century long after most other uses for photogravure had ended.

Postcard

Crayon Gravure: This roadside postcard from the 1960’s reproduces a drawing in pastel or color pencil. It is printed with the same CYMK pallet used in process printing but it looks richer because it is printed in gravure. The loose nature of the drawing leaves much white space on the paper, which in turn makes it difficult to discern any printed texture. The darkest areas as in the lettering are revealing. They have very coarse edges and a body filled with white dots typical of photogravure.




ROTOGRAVURE (Machine Gravure)

Photogravure had been used in commercial printing since the paper fed press was developed in 1863 but there was no way to expose the large metal cylinder of a rotary press to a photograph through a halftone screen. In 1864, J. W. Swan discovered a way of transferring an image onto a metal plate by using a photosensitive gelatin tissue and in 1879, Karl Klic replaced Talbot’s first step of aquatinting a plate by infusing the gelatin tissue itself with a dot pattern. This new tissue was not only able to produce an attractive random grain along with fine detail, Klic’s method provided the most consistent results and it soon became the most widely used. Just as important the use of gelatin tissue would eventually allow gravure to migrate to the rotary press. The tissue could easily be exposed anywhere and later wrapped around a copper coated rotary cylinder. The cylinder could then be etched by rotating it through a tray of acid. Rather than patent and license his invention, Klic hoped his Rembrandt Intaglio Printing Company could keep a monopoly on the process; but when an apprentice left for America he took the secret with him. By 1904 rotogravure was in widespread use and producing countless postcards. While rotogravure was designed for use on a rotary press these plates were sometimes printed on flatbed hand presses.

Postcard

Rotogravure: The postcard above is typical of rotogravure printing. None of its ink cells are visible to the naked eye; instead we are provided with a wide tonal range, smooth transitions, and deep velvety blacks with a matte finish. The process was capable of reproducing artwork with the same qualities achieved with photographs as seen on the card below.

Postcard

In 1908 two textile printers, Eduard Mertens and Ernst Rolffs took rotogravure’s development much further. Rolffs developed a method by which a gelatin tissue is double exposed, first to create a solid crossline screen pattern across the entire surface of the cylinder in the form of an acid resist. This screen will not print but remain white while allowing the square cells between them to be further exposed. The second exposure is then made with the transparency that holds the image, which causes the square cells to harden in proportion to the amount of light filtering through the film image. The tissue is then adhered to a cylinder and the soft areas are washed out with water leaving a hard acid resist behind. The acid bath will incise a continuous toned image into its surface between the screened lines by creating small ink cells of substantial but varying depth. The deeper depressions will transfer more ink to the printing surface creating darker areas while the shallow inkwells will print lighter. The areas of the cylinder that are not etched at all become the non-image areas where the screen pattern completely disappears. In dark areas the fine lines of the screen pattern that were not etched will leave behind a faint white grid around the wells. These lines are too small to be visible to the naked eye especially in areas of black where plate tone tends to spread across the surface to obscure them.

Postcard Detail

Rotogravure: These two details reveal the grid like cell patterns found in rotogravure. While the regular pattern above was created with a typical line screen the more unusual pattern below demonstrates that there were a variety of screen types for printers to choose from.

Postcard Detail

During printing the etched screen cylinder revolves in an ink fountain where it is coated with fluid ink. Eduard Mertens invented a wiping blade (doctor blade) that clears ink away from the surface areas while leaving ink safely in the depressions of the cylinder protected by the crossline grid. When paper passes between the etched crossline screen cylinder and an impression cylinder, its soft rubber covering pushes the paper into the steep incised ink cells and the image is transferred onto the paper. This mechanical inking process sped up printing time considerably and it replaced the old hand inking and wiping methods within two years. Because cylinders were expensive to make they were most often reserved for web-fed presses used for very long runs. For pressruns of a million or more, the cylinders are plated with chromium to provide extra durability. This process was patented in 1910 and was soon being used in commercial printing. While these new changes to the gravure process made it much more commercially viable it was not typically used for American made postcards. In Europe however many monochromatic cards were produced by this method but usually on sheet-fed presses.

Postcard Detail

Rotogravure: Because the ink used in rotogravure is transferred out from deep wells in the plate’s surface it can lay thickly on a paper’s surface once printed. This often forms a rich even tone, which can make this medium difficult to discern. Evidence of the technique can best be found in the inky crust that builds up in the darkest areas while the inherent grid pattern is easiest to observe in the lighter tones that carry less ink. While the detail below seems to reveal white boxes in a dark grid this is only an illusion; the ink is hugging only two edges within each inkwell, and as it spills out over a large area it forms a screen-like pattern.

Postcard Detail

Postcard

Rotogravure: This postcard from 1915 captures so much detail one may think it a collotype though its rich darks are closer to gravure. On close examination the only grain seems to be that of that caused by the papers fibers. It is very easy to mistake this card for a photogravure for it is only in a few of the white details as seen below that the faint pattern of a rotogravure plate shows up.

Postcard Detail

In the later 1900’s gelatin tissue was replaced with a high contrast photopolymer emulsion that was usually sprayed directly onto the copper plated cylinder. This not only creates printed images with higher resolution, it can dramatically speed up production time. Its widespread use however has been curtailed by the introduction of electromechanical engraving based on digital technology.

Monochromes
A color print can most easily be achieved by simply printing it in a single hue. Though most monochromatic postcards were printed in black & white, they can also be found in many shades of blue, green, sepia or dark brown. It is these standard color cards we typically speak of when referring to monochromes. Because these colored inks were produced from common pigments they could be manufactured in large quantities and inexpensively. This allowed publishers to print monochrome cards at a similar cost to their black & white cousins while charging a bit more for the color. Because prints made from a single plate carried a lower density of ink than color prints made from multiple plates their details were often sharper.

Postcard

Monochrome Rotogravure While the blue tones of this postcard image have some associations with a wintery landscape, no rules were generally followed when matching color to subject matter.


The audience for monochrome postcards was much larger in Europe than in the United States. Part of this was due to preferential differences. Most of the monotones popular in Europe were printed in a fine high quality gravure making them more expensive. Price was a more decisive factor in the United States and cheeper lithographic postcards of varying quality were produced instead. Being the easiest to print, postcards of one color have been used since their inception. In postcard’s golden age monochrome cards were just another minor variation to what was then available, but by the 1930’s they became extremely common in efforts to drive down cost. After the introduction of cheep photochrome postcards, the monochrome postcard disappeared in relevant numbers.

Color Rotogravure
Intaglio had largely been an unpopular method for multiple plate color printing because the wet paper used would cause registration problems as it dried and shrank. The texture of gravure however was not nearly as deep as their line etched cousins so less pressure could be used when printing them. This meant that the paper need not be as pliable, so it was possible to dampen it less reducing its shrinkage and improving registration. While many postcards were printed in color rotogravure its complexities and expense kept it from gaining as wide an acceptance with printers as lithography or line block.

Postcard

Color Rotogravure: When printing in color rotogravure, red, yellow, blue, and black is the standard pallet instead of the usual CMYK process colors used in offset lithography. A separate cylinder is made for every color used in a print. In the detail below the typical square cells of rotogravure are still evident despite the over printings of color ink.

Postcard Detail


Postcard

Color Rotogravure: While a black gravure key plate has no problem translating a photographic image, colors always seemed forced as if applied by hand, making the color gravure process more suitable for reproducing illustration. This postcard from 1952 show that publishers saw benefits in this look even when alternative printing methods had become available.

Postcard Detail


Postcard

Color Rotogravure: Even though the details of this postcard lack high clarity, color rotogravure in the right hands could be used to create wonderfully subtle results. High resolution is not always needed because of the minds ability to extrapolate on what it sees.

Postcard Detail


Postcard

Photo Rotogravure: The flatness of the colors on this postcard would suggest it was made through lithography while it actually consists of rotogravure dots in a light red, yellow, and blue. Even though the dark blue printed in a solid gravure tone works as a key, it also displays a more modern tendency to render images more abstractly through color fields rather than line. Here style trumps technique.



Postcard

Color Rotogravure: On this early color rotogravure the darks take on the typical solid crusty characteristics of most work in gravure but the highlights are printed with such fine marks that the technique is almost indecipherable. The small ink wells have created a sharp clean image with fine detail. Note the effort made to render the image in RGB colors even though a RYB pallet was used.

Postcard Detail


Postcard

Color Rotogravure: Modern rotogravure is now capable of producing much richer color mixes. While the process as used here has not created the natural color that is often associated with photochromes, it has manage to remain competitive by producing a rich and enhanced color mix reminiscent of a hand colored photo. Technique is no longer affecting appearance as much as a desired look is determining technique. In the detail below the gridlines of the plate are clearly visible due to the large inkwells, which also help give the image a softer look.

Postcard Detail




PHOTOLITHOGRAPHY


During the 19th century lithography’s dependence on a substrate of heavy limestone nearly doom this promising medium to oblivion. Photographic transfer was very difficult and stones could not be used on fast rotary presses while metal litho-plates were found to be too fragile for extended commercial use. Line block printing, which became its chief competitor, may have overtaken it had it not been for the invention of gelatin tissue. This inovation caused revolutionary changes in lithographic reproduction and returned it to the status of a competitive medium. It would be used to create a new generation of multi color postcards just as traditional chromolithography began to fade. Most early photolithographic techniques would be abandoned by the 1920’s but color lithography would continue to evolve into photo-offset lithography, which is used to produce most of the world’s postcards today.

Photolithography
Sometime around 1852 the French printer Rose-Joseph Lemercier became the first to create a photolithograph. His process basically began by coating a litho-stone with a thin layer of photosensitive asphaltum, which was then exposed to paper negatives. Three years later Alphonse Louis Poitevin patented a similar method, only his process used a photosensitive emulsion of dichromate in albumen or gelatin that was applied directly to the substrate. All early photographic transfers however were made through contact printing with exposure from the sun, and the size and weight of the stones made this procedure very difficult and not commercially viable. This problem was solved in 1864 when J. W. Swan invented a gelatin tissue that could also be photosensitized and exposed away from the substrate, and then later adhered to a stone’s surface. After exposure to a photo negative and washed out, only the light hardened gelatin will remain on top the stone as if it were a drawing. When the stone is dampened and rolled up with a greasy ink, the moisture will sit within the fine polished surface of the bare stone, and the rolling-up ink will only stick to the remaining photo emulsion. It is then lightly etched to chemically stabilize the image on the substrate. Once cleaned it can be printed as a normal lithograph.

Zincography
Zincography was an early form of photolithography designed for use on metal plates. A zinc litho-plate was first coated with a mild acid solution that caused hygroscopic salts to form across its surface. A photosensitive asphaltum varnish was then applied and the plate was exposed to a positive transparency. All areas that were exposed to light would harden. A bath of acetic acid would wash out the rest of the asphaltum and deposited salts except those trapped under the harden areas. The plate would be coated once more only now with a dark lacquer varnish (fuchsine). Parts of this coating would then be washed off with solvent but it would continue to stick to the areas where the asphaltum had hardened. When dampened and rolled with ink the salted areas would hold water and repel ink while the remaining lacquered coating repelled water and attracted ink. As the use of litho-stones diminished, the term zincography was largely forgotten and work printed from photo generated litho-plates is now simply referred to as photolithography.



PHOTO-CHROMOLITHOGRAPHY

While the photocrom process was a new type of photo based technique, it was in many ways really little more than the natural evolution of chromolithography in the face of advancing technology. Many separate printing substrates would still need to be created for each tone of the same color as there continued to be minimal use of optical blending. Just as the pallet for chromolithographs seemed to be narrowing, the photocrom process reversed this trend and expanded the use of colors. Only now random photographic grain and speckle would replace artist drawn dots and spatter. This technique provided an outlet for the public’s fascination with photography while retaining the look of chromolithographs that they were comfortable with. Despite the fact that many of the postcards created were far from the truthfulness of a photograph and in the colors of nature that their catalogs boasted of, this was a winning combination that attracted a large market. While a number of companies would develop and even patent similar techniques, those who actually used this process were so few that variances can be examined through each firm.

Postcard

Photo-Chromolithograph: This postcard seems as if it were only printed in three RGB colors when actually nine were used. Three values of the same relative hue were each created with a different plate, which is more noticeable in the enlargement below.

Postcard Detail

Photochromie (Vidal Process)
An early photo-chromolithographic process was invented in 1875 by Frenchman, Leon Vidal that combined traditional chromolithography with elements of the photographic reproductive methods used to create woodburytypes. Duplicate glass plates were made from the same negative for each color required and then the areas not needed to print were covered with opaque ink. These transparent colors would then be printed over a photograph or a woodburytype. This technique produced very high quality reproductions but it was such a difficult and expensive process that it was rarely used. After some modifications that created an image entirely in ink, the firm of Nenke & Ostermaier obtained a patent for the photochromie process in Saxony that was based on Vidal’s earlier work. At first they used it to print postcards for other publishers but eventually they began to publish cards under their own name.

Postcard

Photochromie: The details of the rocks on this postcard by Purger & Co. are so realistic and minute they could have only been based on a photograph despite the coarsely printed grain. The train however is very rigid in appearance indicating it was either heavily retouched or completely drawn in.


Postcard

Photochromie: Even though the areas of color on this postcard by Nenke & Ostermaier are too localized if not also too intense, it still holds a very strong photo like appearance that hints at its origins.


Photochrom Process (Aäc Process)
This continuous tone color lithographic process was developed in Switzerland in 1886 by Hans Jakob Schmid of Orell Fussli & Company and patented in Austria in 1888. The Swiss firm Photochrom Zurich later renamed PhotoGlob was specifically set up for the printing of postcards and prints with this process. They later licensed out this technique to Photochrom Ltd. of England, and the Detroit Publishing Company in the United States. The precise details of this method varied by licensee, providing each company’s cards with a distinctive look. For the most part the use of this process ended in the 1920’s as publishers sought out less expensive alternatives but it was still used in Switzerland up until 1970. Today a nearly identical look can be achieved with screenless offset lithography that uses only four process colors.

Postcard

Photochrom: Unlike the color fields in traditional chromolithography where many multiple color dots were employed to create a more subtle appearance, the color fields in postcards by Photogob were made up of small markings of very similar hues. While this provided their cards with greater color intensity, it also flattened out the space in many of their compositions. The dichotomy between detailed rendering and flat color as seen in the two details below created a distinct mannered look that was typical of photochroms.

Postcard Detail

Postcard Detail

The Photochrom process begins with litho-stones coated with a photosensitive Syrian asphaltum (bitumen) dissolved in benzene, which when dry are then all exposed to the same photo negative through contact printing. No line screens were used in any part of this process. The asphaltum hardens in proportion to its exposure to light, and the unhardened areas are then washed away with solvent. At this point the retoucher removes all parts of the image not relevant to the color assigned to that stone (photo-stone) while adding in needed texture. Wool daubers and fine hairbrushes were often used with touche to finely adjust the tonal balance, which required a very delicate hand. In some cases new compositional elements would be drawn in. Each stone then went through a very complicated etching process where most of the technique’s secrets lay. This manipulation of processing variables determined the nature of how and where the ink grain printed that controlled the postcards final look. The stones were then printed in the same manner as a normal chromolithograph. At least six separate stones were required for this process though the employment of ten to fifteen hues was more typical. The resulting images though completely broken down into small granules could capture a fair amount of detail with a great clarity of color; but since they were based on black & white photographs the handling of color by retouchers could render the same image realistic or highly mannered.

Postcard

Photo-Chromolithographs: While photo-chromolithographs usually have a strong photo-like continence despite their rough grain, extensive retouching can often defeat this look. Colors have been so altered on this postcard above that they not only appear unreal, they distort the pictorial space. The limited pallet on the card below has produced a dull image more typical of a tinted halftone than one produced through this medium.

Postcard

In 1888 the Wezel & Nauman Fine Arts Company patented their own photocrom process in Germany a day after Orell Fussli filed their patent in Austria. From about 1890 most of their postcards were printed on artificial lithographic stones, a product of their own invention. Through the use of acid and grinding the unusable remnants of true litho-stones were reduced to a pulp to which asphaltum, resin, and oil were added. This mixture was then sprayed onto a zinc plate in a fine even coating. When it had hardened it was drawn upon and processed in a fairly traditional manner.

Postcard

Photochrom: The colors and grain on the photochrom postcards published by Wezel & Naumann tend to combine into very soft ethereal blends. It is often only through the use of color contrast that details and a readable composition emerges. In the background a minimum of contrast is used to help the space recede but in the two details below we can see how distinctions begin to disappear when the image is reproduced in black & white.

Postcard Detail

Postcard Detail

In 1896 the Photochrom Company took over Fussli’s London office established three years earlier and began publishing similar postcards after securing the exclusive English license for the Swiss photochrom process. This technique was used to produce a great number of view-cards of Europe. While they captured the same fine details as the Swiss prints their pallet was much softer and often reduced.

Postcard

Photochrom: The different color grains used in the Photocrom Company’s postcards tend to be printed in high contrast to one another within any single area. While this created less harmonious color fields it had the effect of uniting the entire composition.

Postcard Detail

Phostints
The Detroit Publishing Company began utilizing the Swiss photochrom process after licensing it in 1897, and they eventually applied their own trade name Phostint to it in 1903. Not only did they alter the specifics of this process to give the postcards and prints they produced a unique look, they did much experimentation causing their postcard production to undergo a number of technical changes during the company’s history, which continually altered the appearance of their cards. Phostints are based on creating a continuous toned lithographic image through directly exposing a negative through contact printing to a stone photosensitized with a coating of syrian asphaltum. By there careful control of the asphaltum in relation to its processing etch they were able to manipulate images in countless ways. It is even possible that they may have combined this technique with elements of the Vidal process. While typically six to sixteen litho-stones were employed to print all the different colors needed to create a single phostint image, many more optical color variations were possible through their careful alterations of each stone.

Postcard

Phostints: The phostint process was always being tinkered with resulting in cards with different qualities. Though the early Phostint above was printed with a number of plates an RGB pallet dominates its color scheme. The card below, printed at least six years latter uses much brighter hues and is generally sharper in appearance.

Postcard

There have always been differences in color when any company reprinted their cards, but Phostints became known for their wild color shifts that could render two or more very different images from the same photograph. This however has more to due to decisions made by retouchers rather than any technical aspect of the process. There was great latitude in color choices since these cards were made from black & white photos that were only occasionally accompanied by specific notations regarding the placement of hues. By redesigning through alterations in processing a single photograph could yield a variety of postcards that may appeal to a larger audience.

Postcard

Phostints: Both of these very different postcards were produced by the same Phostint process and from the same photographic negative. Part of the difference is derived from a change in pallet but more importantly from the way in which each of the stones used were etched.

Postcard

Postcard Detail

Phostint Details: In these two details from the cards further up we can see the use of brighter reds on the example above but contrast is also darker due to a more dense accumulation of black. On the detail below there is a heavier use of black as a fine grain throughout the image that lowers its overall color saturation.

Postcard Detail


Postcard

Phostint: Because Phostints were photo based it is often easy to forget how extensively retouched they were. In this crowded composition the retoucher left the background nearly flat and colorless to bring our focus to the activity up front. Despite the background’s neutrality these tones are actually made up of at least three different hues.


Because of the fine tonalities, details, and rich color this process created, Phostints were often referred to as the Cadillac of postcards. This reference cannot just be considered hyperbole for in an age without color photography they were able to create images that combined the beauty of an artist’s pallet with precise photographic detail. The particulars of their methods were kept such a close trade secret that when Detroit Publishing went out of business in 1932 there were only a handful who knew how to make a Phostint from start to finish. During their last days their furnaces consumed all written documentation along with leftover cards and working proofs in an effort to provide heat for their factory, and the techniques they so carefully developed over the years died with them.

Postcard Detail

Phostint: Photo-chromolithographs often give the impression that they capture details well, but as we can see from this long detail of a phostint this is only a half-truth. The image is made up of a conglomeration of small markings that are even more irregular in size and shape than found in traditional spatter techniques. Seen close up they do not hint at their photographic origin but even with the absence of a key plate the very strong overall photographic resonance is able to create definition.


Photochrome Process
In 1935 the Photochrome Process Company was formed by some of the former employees of the defunct Detroit Publishing Company in an attempt to revitalize the Phostint printing process. While they printed postcards until 1940 they were unsuccessful in capturing the look of the originals. Where the individual markings in Phostints retained sharp edges, Photochrome cards have a soft ill-defined look that rendered a similar matte surface as those produced through gravure but without the same richness. Many now refer to the finish of these soft dull cards as frosted to distinguish them from the similar images that were previously printed by Detroit Publishing.

Postcard

Photochrome Process: Memory proved faulty in the absence of documented procedure, and the Photochrome did not match the vitality of the Phostint. This is mostly due to the different way that the ink sits on the paper.


Poly-Chromes
Poly-Chrome was a trade name used by the American News Company for their screenless photo lithography process. The texture on these cards is similar to that of the Photochrom but they all tend to lack their fine grain and they can be more generally characterized as having broader flatter shapes. Their texture in fact is much closer to that of a chromolithograph with a heavier amount of retouching but this is obviously a photo-based process.

Postcard

Poly-Chrome: In this postcard from 1906 we can find flat tones similar to the Swiss photochrom process but little of its fine grain. There is much evidence of heavy retouching in the darks as seen in the detail below.

Postcard Detail


Postcard

Poly-Chrome: When a picture on a Poly-Chrome is broken down into less flat fields its photographic base helps create a much more realistic image. This has more to do with the choice of composition than from any changes in the manner in which it was printed. This postcard was heavily retouched with additions of small flat blots placed underneath the fine photo grain.


Most Poly-Chrome postcards seem to have been published by the American News Company between 1903 and 1907, but the same name and logo can be found on much later cards published by other firms. These late cards however were almost always produced in an entirely different technique. A few other publishers produced similar photo based postcards through screenless lithography in combination with traditional drawn techniques. Many such cards were produced in Europe, possibly from the same printing firm without any reference to technique or publisher.

Postcard

Photo-Chromolithograph: This postcard published by Chisholm Brothers makes no reference to technique but it is very similar to a Poly-chrome. While it uses screenless lithography, mostly in black and grey to create its photo-based composition, there are also obvious signs of retouching as in the addition of many hand drawn yellow dots.


Photo-Chromolithography
While we know who all the major publishers were in photo-chromolithography there seems to be many more subtle variations on this process than there are known licensees for. Part of this problem is caused by the large amount of postcards out there that are not attributable to anyone. Most of these types of cards may have simply been contracted out to the major firms who had the ability to produce them, but they could very well be the result of other printers who discovered similar methods of production. These methods may be truly unique or they may infringe upon registered patents creating a reluctance to supply attribution. Patents become difficult to enforce, especially over international boundaries when all parties involved desperately want to hide their trade secrets. Photo-chromolithography was truly one of the Black Arts.


Postcard

Photo-Chromolithograph: While this postcard published by Hugh C. Leighton lacks the varied coloration found on many photo-chromolithographs, its texture is unmistakably of one. All cards in this series are characterized by a limited pallet with a dominant orange hue, which gives them a more hand drawn look.


Postcard

Photo-Chromolithograph: There are a good number of photo-chromolithograph postcards about where the publisher is unknown as on this Russian postcard. The process however can still be identified by closely examining the clumpy details of the grain.

Postcard Detail


Postcard Detail

Photo-Chromolithograph: While photo-chromolithographs are made up of small dots they tend to be very irregular in shape and size and do not have the same patterning as the hand drawn dots of a chromolithograph even when placed down in a haphazard manner. In both these details we can sense they are more the result of a photomechanical process but careful observation must be made to filter out this texture from the work of retouchers.

Postcard Detail



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