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Photography and the Black Arts


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Once photography was invented, it was soon discovered that the time consuming process of making photographs could not meet demand. Efforts were then made though out the latter half of the 19th century to find the cheapest and fastest way to reproduce photographs in printed form. A plethora of techniques were developed, most would based on variations of the photo gelatin process, which became the foundation of all photomechanical reproduction. While the basics principals are simple and well known, many nuances in practice produced unique results. With a growing reliance on photography to produce inexpensive imagery, the printing trade’s dependence on artists shifted even faster to that of technicians. Industrial espionage grew to be so prolific that printers became very secretive, so much in fact that many of these photo gelatin processes have been lost to us over time. There was so much mystery surrounding photography in general and so much secrecy in protecting discoveries that these almost magical techniques were sometimes referred to as The Black Arts.

The use of photography in printing has unleashed a dilemma when trying to ascertain printing techniques. While most methods should ideally be identifiable at a glance, great efforts were often undertaken to make printed work in one medium look like another. Very often a more economical printing method tried to emulate the look of an expensive one. This was usually done to attract customers, not to create forgeries. Sometimes a popular look just became too expensive to print commercially so look a likes were made instead. Advancements in technology often outpaced public taste. Certain graphic styles also developed around specific printing technology, and when a process evolved into something new the old style often followed as best it could even when it was no longer well suited for that medium. This is inevitably a problem in all art reproduction whether it is a copy of a museum piece or of an illustration specifically designed for a postcard.

This section only concerns itself with photography’s initial affect the printing industry. There is further information on the development of photography in the separate Guide to Real Photo Postcards.




THE ROTARY REVOLUTION

The flatbed cylinder press, first used in conjunction with relief printing, evolved from the early rolling presses used for intaglio work. After an iron or steel frame (chase) designed to contain letterpress type and line block images is locked together creating a form, it is then placed on the flat bed of a press while paper is fed on top of it from a long paper web. Both surfaces are then pressed together with a heavy metal cylinder and individual sheets were cut afterwards. Much commercial work had switched from the bed and platen press over to the speedier cylinder press that became its chief competitor before the middle of the 19th century. The cylinder press proved essential for large scale production required by newspapers and large book editions but it was not well suited for printing smaller items in more limited quantities. Even so it could only print one page at a time, about 250 per hour as the press bed slid back and forth under the roller. The cylinder press however inspired the running of fed paper between a pressing roller and a second roller incised with an image for continuous printing. Unfortunately this promising new technology that could use large rolled paper webs created a dilemma for governments that relied on taxing paper for much of their revenue. At this time each individual sheet of paper manufactured required a tax stamp to be sold with it, and the innovation of paper webs threatened this long standing arrangement. Hampered by official policies in Europe, this revolutionary press design would first be put to large scale use in the United States.

Illustration

Web Rotary Press: This old wood engraving illustrates the earliest version of the Hoe Rotary Web Press.


The Rotary Press
Between 1750 and 1850 numerous versions of a rotary press were invented. They had already been in use for some time for printing on fabric but little is known about them. The Englishman, David Napier who had made many improvements to the cylinder press patented a design for a rotary press in 1837 but did little to put it into production. It was the rotary press patented in 1844 by Richard M. Hoe of New York City that would revolutionize the printing industry. It consisted of one large roller into which columns of type were fitted surrounded by a number of smaller impression rollers that applied pressure to the back of the paper. A separate image could be printed simultaneously for every impression roller present with only one revolution of the large type holding roller. Unlike the roller of the cylinder press that would turn back and forth with the press bed, Hoe’s roller would continuously turn in only one direction. Printing speed was determined by how fast this roller could be made to rotate and how many impression rollers could be fitted around it. While this press used hand fed sheets of paper, another design that would accept and cut web fed paper was invented by William Bullock in 1865. Hoe and Bullock would work together to make many additional improvements to rotary presses. By the 1890’s there would be a variety of rotary presses available, and within ten years most of these steam driven machines were electrified. As presses were motorized they became ever faster, and with electric power a whole range of new features could be added to them.

Postcard

Sheet Fed Rotary Press: This card shows color postcards being run off of a sheet fed press at the Art Manufacturing Company. Note that many different cards can be printed on a single large sheet at one time for the sake of economy. This is known as gang printing.


A major problem with HoeÕs early rotary press was in the way type was clamped into curved frames (turtles). This delicate mechanism tended to break under the physical demands of the press, and loose metal type flying off at high speeds caused serious injuries. A solution was found by making a papier mâché mold of the type while arranged in its form. This flexible paper mold (flong) could then be bent to the same curved shape as the press cylinder and a two-piece lead casting made from it. The two halves of this curved plate could now be tightly fitted over the roller and bolted together. Many claimed responsibility for this innovation but David Bruce might have been the first to use this method back in 1812. By 1851 Hoe was manufacturing stereotypes by machine to meet growing demand. Stereotyping not only provided an efficient and safe method of adhering type to a cylinder, it was also a way to add on pictures. Since stereotypes were cast, more than one copy could be made, which meant that multiple presses could be employed in printing the same image for large runs. The process proved to be adaptable to presses of ever increasing speed insuring it would have a long life.

Postcard

Stereotyping: This postcard illustrates the manufacturing of stereotypes for the printing of newspaper pages at the Philadelphia Record.


The rotary press increased production speed by such dramatic levels it simply could not be ignored even though not all the accompanying technology had yet caught up with the process. This dilemma initiated a scramble to find methods capable of adapting all popular printing mediums to it. Photogravure was able to reproduce photographic images since mid-19th century, but this technique was not compatible with the new fast rotary presses because there was no way to evenly expose a cylinder to film. Problems also existed with lithography where the heavy stones that received the image could not be bent, and their planographic surface could not be cast. The alternative thin metal litho-plates that were flexible proved to be very delicate and they wore out too quickly on these new presses. Competition had grown fierce and technologies that could not keep up with increasing demand for printed matter at lower prices faced extinction.

Flong
All sorts of substances have been used to make molds of a plate for stereotyping from starch to custard flan. By the 1820’s it was papier mâché alone or in combination with other substances was most often placed onto the lightly oiled form with a stiff brush making sure it covered every surface with precision. This became known as the wet flong method after the alternative dry flong method was invented in 1892. Here a thick sheet of pliable paper is pressed into the heated form under great pressure until it takes on its every likeness. After it is dried with a dusting of talc it is then bent to create a stereo mold ready for casting or electroplating.




PHOTOMECHANICAL PRINTING


There are many different examples of printing surfaces that were created with the aid of photography. Some of these methods have been given trade names similar to that of specific techniques, but one must be careful not to read too much into them. Commercial names were often applied to a postcard to reference the look of a specific printing method. While this labeling might enhance its marketability, the postcard could be manufactured with any lookalike process. Others have also wrongfully used the names of very specific techniques, applying them to other mediums of which they bare little resemblance. This habit is most often true when an obscure technique is in question.

Photosensitive Gelatin
Gelatin is a colorless, transparent, brittle protein extracted from the skin, bones, and connective tissue of animals. Fish skin and tails were often used to make it and it is sometimes referred to as fish glue. Through a long curing process utilizing acids and alkalis, the molecular structure of collagen is broken down into a substance with weaker molecular bonds creating gelatin. The nature of gelatin is to be absorbent; it swells in cold water and dissolves in hot. In 1839 the Scot, Mungo Ponton discovered that when a dichromate is added to an organic substance it becomes photosensitive. When mixed with gelatin and dried, it loses its absorbent qualities once exposed to light. This gelatin emulsion could easily be applied evenly to papers and any flat printing substrate. When areas of a photosensitive emulsion were exposed to light and other areas masked, as with a photographic negative, the exposed areas would harden while the remaining gelatin could be dissolved and washed out with water. In this way an image in low relief could be formed. This concept became the basis of all photographic reproduction.

Cliché Verre
The earliest attempts at producing photographs were not made with a camera but through the contact printing of objects against photosensitized material. William Henry Fox Talbot had been experimenting with salted papers and silver nitrate for five years before publicly announcing his discovery of photogenic drawings in 1839. He had pressed both lace and plants against photosensitized paper, which was then exposed to the sun. The resulting print was nothing more than a white silhouette against a dark background but it still had great potential in accurately capturing certain information without bias.

Real Photo Postcard

Cyanotype: This homemade cyanotype postcard was made by photosensitizing the paper with ferric ammonium citrate and potassium ferricyanide. A black drawing on a transparent film was then placed over the card and contact printed with sunlight. This causes the iron compounds to oxidize, yielding a photographic image in a flat Prussian blue once it is washed out. The ease of creating cyanotypes made them popular with amateur photographers at the turn of the century, but the technique was not used in producing commercial postcards.


This principal was expanded upon by artists in the 1850’s who would coat a glass plate with soot from a burning tallow, then draw into it with a needle before exposing this makeshift negative to light sensitive paper. The soot was eventually replaced with a more stable opaque coating painted onto the glass that allowed for a finer drawing. The photographs created resembled the line work of pen & ink drawings or etchings only without the typical intaglio relief. Sometimes an extra glass plate was placed between the drawn plate and the photo paper so that the light would diffuse the image during exposure and render a softer look. This process became popular in France where it was known as cliché verre (glass picture). While its use generally ended in the 1870és its application can occasionally be found on a stray real photo postcard from the early 1900és, but in a form that produced white lines on a black backdrop. A positive transparency was simply exposed to photo paper that would normally be exposed to a negative. These same principals would also be applied to postcards printed in ink with line block. Clichˇ verre has been used in various forms throughout the 20th century but mostly by artists. Today the process is represented in digital form as scanography.

Real Photo Postcard

Photo Postcard: This postcard was made using the principals found in cliché verre. It is doubtful that this image was scratched out from an opaque plate because of the exactitude of the large amount of accompanying text. A reverse negative was most likely used in its production or a drawing on film.


Galvanism (Electroplating)
While investigations into galvanism date back to the 18th century, a useful understanding of it came slowly. It was not until 1840 that Thomas Spencer and John Wilson patented a process that could electroplate metal with the use of a Voltaic battery called electro-etching or electro-tint. This was achieved by running a direct electric current through two inert containers (galvanic cells), each containing a copper plate suspended in a copper sulfate solution. The solution acts as an electrolyte that deposits positively charged copper ions on the negatively charged plate (cathode) while etching away the positive plate (anode). This form of etching is actually oxidation, which creates more copper sulfate by removing copper ions from the plate, thus keeping the electrolyte solution in a constant balance. This tends to make it seem as if the process is transferring particles of copper directly between the two plates but this is only an illusion. The resurfacing of plates with harder metals through galvanism grew to play an important role in the printing trades because it allowed more images to be pulled from plates before they wore down.

Illistation

Electroplating: This early illustration depicts a shop designed for electroplating.


Photogalvanography
In 1854 the Austrian, Paul Pretsch patented one of the earliest forms of photomechanical reproduction named photogalvanography to distinguish it from more common forms of electrotyping. His negative charged copper plate would be first coated with a photosensitive dichromate gelatin emulsion then exposed to a negative image. The areas exposed to light would harden and the remaining gelatin was washed out in water forming a reticulated relief. The substrate was then electrotyped until its entire surface collected enough positive copper ions to form a hard coating thick enough to preform as an intaglio printing plate. The crevices formed by the reticulated gelatin on the original could now be made to print in a manner similar to that of an aquatint. Two years later his Photo-Galvanographic Company was producing plates for the printing trade. Photogravure replaced photogalvanography for most commercial work during the 1870’s but its principals would remain important for the development of the collotype, ink photos, and stereotyping.

Goupilgravure
In 1872 Henri Rousselon of the French firm Goupil & Cie developed an exclusive process similar to photogalvanography that was used extensively for art reproductions. He found a way to alter a dichromate gelatin emulsion so that it will crystallize under exposure to light When painted onto a plate and then contact printed with a negative, the unexposed areas remain smooth and flat, while the crystals grow coarser in proportion to the amount of light they were exposed to. Afterwards the plate is electrotyped in copper to harden its delicate surface. These plates could print a full range of tonal values with the coarsest areas that hold the most ink printing darkest. While the results seemed incredible at the time, this process had difficulty in capturing details within the lighter tones, and much time consuming hand work was needed to correct this flaw. While most of these images were printed in black & white, color inks up to twenty in number were sometimes painted directly onto a single printing plate to reproduce the effect of watercolor.

Photoxylography (Electrography)
There was a growing problem with wood engraving even while it became the staple of 19th century illustration. While methods of adapting type to the new rotary press were succesfully developed, the thick hardwoods engravings were made on could not bend. This problem was eventually solved by a method of electroplating in which wood engravings can be cast in metal for use in xylography. A papier mâché or plaster cast is first made of the wood block then the inside is coated with a very thin layer of lead. By placing the coated cast and a sheet of iron into separate electrolyte solutions containing iron, the iron particles will slowly deposit themselves onto the lead when an electric circuit us run between the two containers. This process continues until it forms a sturdy duplicate of the original image. This metal replica could be made strong yet thin enough to be stereotyped onto a rotary press when a large press run was need.

Photo Wood Engraving
Wood engravings often suffered when accompanying news stories because of their lack of accuracy. In the face of looming deadlines, the artist that needed to draw the image often had little more to go on than a field sketch or brief written description. Much of what ended up before the public was only an artist’s interpretation of events. This situation improved by 1860 when the Englishman Thomas Bolton discovered a method by which the end grain of a woodblock could be photosensitized. After being contact printed with a negative, the block wasn’t processed for printing; the transferred image only acted as a guide so that a more realistic image could be cut into it. While this new method saved on production time and presented the news with more accurately, it wasnÕt appreciated by all. Many found the images produced to have a sterile commonality about them despite their beauty since artists were cut out of production. Engravers were no longer cutting to faithfully capture the artist’s lines and inflections, they were carefully rendering tones as accurately as they could with the maximum economy. Even with increased efficiency, highly skilled craftsmen were still required to engrave the image and it remained a slow and expensive technique. By the time postcards came into vogue, this process was already in a steep decline due to its high cost and alternative halftone methods being readily available. Illustrations made in photo wood engraving are most likely to be found on pioneer advertising cards where certain products needed to be rendered in detail by an unbiased hand.



COLLOTYPE

The collotype is a continuous tone printing process first patented in France by Alphonse Louis Poitevin in 1855 under the name Phototypie. It began to be used commercially as the Albertotype in 1868 after Josef Albert in Germany perfected the method, but when patented in the United States one year later it was given the name Artotype. The technique begins with a greyed glass plate coated with a photosensitive dichromate colloid gelatin that puckers and cracks as it dries. When exposed to light through a reverse negative, the lit areas harden into an insoluble nonabsorbent finish. It is the areas within the reticulated cracks that harden the most because they are the thinnest part of the emulsion. They in turn will print the darkest in proportion to the tones of the original image. The dichromate emulsion in areas with little or no exposure to light remains soluble and is washed out from the gelatin with cold water. The plate is then printed in a similar manner to a lithograph. A solution of glycerin and water is spread over the plateÕs surface, which is absorbed by the remaining gelatin. Areas that are to carry the dark tones absorb little or no moisture while areas for the lighter tones and non-image areas absorb the most. When greasy ink is rolled over the gelatin on the plate, the non-image areas holding the most moisture repel the ink, and the dry hardened image areas attract the ink. Once printed the reticulated pattern creates a continuous toned image of incredible detail for which it is prized.

Postcard

Collotype: This early Swiss postcard clearly demonstrates the tremendous delicacy in tonal range that can be achieved through collotype printing. When collotype cards were made from poorly exposed photographs they where unable to show off such subtleties as seen on the card above.


During the 19th century the collotype process was best known as Artotype, the name given to it by Josef Albert. Many others however elaborated on the process and trade names such as Hoeschotype, Inkphot, Paynetype, Photopane, Photo-type, and Albertype abounded. Some became more widely used than others and a number of different variations on this method were used to produce postcards. In 1868 the German Max Gemoser developed an important variation, which became known as Lichtdruck. The gelatin skin was removed from his processed plates and remounted onto litho-stones for greater support during printing. Despite certain shared characteristics, collotypes are not always easy to identify do to natural variations in the drying gelatin and numerous trade secrets. With no set standard the most uncommon collotype patterns may be difficult to distinguish from photogravure.

Postcard

Collotype: The fine grain of collotypes with their white centers have a barnacle like look since the ink prints from the reticulated surface the plate. Though similar to the grain of aquatint and variable in size, the wormy look caused by the gelatin curdles is usually a dead giveaway in identifying the technique. This however can only be observed under extreme magnification as the close and closer details below of the postcard above demonstrate.

Postcard Detail

Postcard Detail


Postcard Detail

Collotype: Elaborations on the collotype process were a very secretive matter as they could produce unique results. While the detail above and below are enlarged to the same proportions, one collotype has a small aquatint-like texture and the other a bold reticulated pattern.

Postcard Detail

The greyed glass plate used to make collotypes was a major drawback for the process; it is very fragile and its shallow gelatin surface can rarely yield more than 500 impressions. Some have claimed to have pulled 2000 images from a single collotype plate but this may be an exaggeration. For large orders a new substrate would often have to be prepared substantially adding to the cost. Gelatin plates did not age well due to their organic nature and could not be stored for long periods to print at a later date. They were routinely scraped down after printing so that the glass could be reused. This severely limited the commercial applications of this process, but it proved adequate for small press runs and was widely used in postcard production. Glass was used as a substrate because it was one of the few materials that gelatin would adhere to in a thin even coat, but after August Albert discovered a way to mount a collotype emulsion onto an aluminum plate in 1896, this medium became easier to use and was finally adapted to the rotary press. Glass plates were still preferred by some printers who continued to use them into the 1960’s. Even when working with metal plates, the delicate gelatin emulsion still needed to be treated more carefully than other substrates, which slowed down production time. Even factors such as high humidity could severely limit their production; and they were usually printed in places where the weather was more stable. Despite all these drawbacks, collotype was still used to produce more black & white postcards than any other technique.

Postcard

Collotype Press: On this old French card we can see other postcards being printed in collotype.


There were no special presses built to print collotypes, perhaps due to all the secrecy that surrounded this process. The image is usually transferred to paper on a modified lithography press or sometimes on a flatbed cylinder press. Its use in commercial printing greatly expanded after 1873 when a way was found to print collotypes with steam powered presses. Though it still remains the most accurate reproductive printing method available today, the process was largely abandoned in the 1990’s in favor of high resolution digital technologies. An order placed for real photo postcards in the early 20th century might be filled with printed collotypes nearly half the time because the resulting images were so similar that the two methods were generally considered interchangeable.

Heliotype
In 1869 the photographer Ernest Edwards developed his own version of the collotype process, which he called Heliotype, and placed an English patent on it the following year. In this method a gelatin dichromate of potash is hardened with chrome alum on a waxed greyed glass plate. The alum reduced the swelling of the gelatin making it more leathery, thus more durable. After exposure under a negative, the gelatin skin was stripped off and briefly exposed on the reverse side to harden it. The skin could then be attached to a metal plate with a rubber solution, and developed in a water and glycerin bath. This process usually required the rolling on of two inks on one plate. A stiff ink that only adhered to the most light exposed areas was used to create the dark shadows, while a thinner ink was used for medium or light tones. The blacks created by this process are much darker than on an ordinary collotype. They can leave an inky crust on the surface of the paper that can easily be confused with photogravure. Over the years the terms collotype and heliotype began to be used interchangeably, and as other printers made modifications to this process it has become difficult if not impossible to definitively identify on every occasion. Many double rolled prints were simply labeled collotypes.

Postcard

Heliotype: The texture on this postcard from 1905 clearly resembles the reticulated pattern of a collotype but the dark tones are much darker than what would normally be expected. In the detail below we can see in some areas they have filled in creating a nearly solid black.

Postcard Detail

Tinted Collotype
Many collotypes used simple color in the same manner that tinting plates were used on early lithographs. This lowered contrast within the composition while expanding the tonal range. Sometimes this process was used in combination with a flatly printed lithography plate, while at other times two collotype plates were made from a single photograph to produce a more elaborate image. In this manner the collotype process could push its darks to the limit on one high contrast plate while still producing vast areas of dense but detail catching light tones from a second plate.

Postcard

Single Tint Collotype: The black image on this postcard was rendered through collotype while the tinted backdrop in fawn was printed in solid lithography with specific areas removed for highlights. This style was first heavily used for tinted lithographs meant to reproduce a traditional drawing in charcoal and chalk.


Postcard

Triple Tint Collotype: The black collotype on this card is printed over fawn, brown, and green lithographic dots. While this same palette could be used to create a more realistic color image, it is largely used here as a tint despite its localized application. Even though tints are usually applied to only create tones, they can often be read as color. This dual function can blur definitions.


Postcard

Color Collotype: This postcard was printed from two collotype plates, one inked in brown, the other in blue. While this could be considered a color collotype, the blue here only functions as a tint that provides no detail. The use of color on this card is overly simplistic. It seems to have been added for the sake of color without regard to its effect on the composition.


Duotone Collotype
There are heliotypes that employed extra hues without using them as tints or to create a color image. While extra color would shift the color balance, many of these cards were already printed in monotones. The real purpose of this technique was to create a richer more appealing image by extending the cardÕs tonal range. A variety of colors could be used, but one was always dark enough to function as a key, and the other was always lighter to better capture faint tones. Ideally these cards were printed from two different plates where each color could be better exposed to capture lights or darks. Areas to print highlights could thus be exposed to create a heavy density of markings because the light color now carried the value instead of an optical mix of black ink with the white paper. The higher density of markings captured more detail and created more subtle tonal transitions. The dark key plate could then be exposed to bring out as much detail as possible without fear of loosing detail in the highlights since they would be printed by the other plate. Sometimes both colors were printed from a single plate by inking it twice, but the improved tonal range was far lessened since the plate only received one exposure.

Postcard

Duotone Heliotype: This unusual collotype postcard was printed with two colored inks from two different plates; one used as a black key, the other a light blue for a tint. While the blue reduces contrast and adds color in a very simplified way, it also carries some of the lighter details as seen in the sky. Note that it was titled in red ink added through letterpress.



Postcard

Duotone Heliotype: The technique used in duogravure was also applied to printing in collotype. This postcard was printed from two plates, one holding a light reddish brown and the other in a dark brown. In the detail below, the collotype texture can be seen printed in two distinct colors.

Postcard Detail

Postcard

Luxusdruck: The Harbor scene pictured above was made as an ordinary black & white collotype, while the card below of the same scene is printed as a dutone. Not only is there a color tint, but the process added in lighter values. While this enabled more detail to be placed into the sky, it lowered the contrast in the water dulling the shimmering effect. When a German publisher charged more for a formally black & white image reprinted in a more elaborate manner, the term Luxusdruck (Deluxe) was required to be placed on its back.

Postcard


Tritone Collotype
Some color collotypes borrowed the two ink model from the heliotype process; but instead of using multiple plates to produce dark shadows and a medium tone, different hues would be substituted. The use of color inks however did not always work well on plates designed to carry value. Images printed with inks of a similar hue usually provided the most appealing outcome, but often dispirit colors were used to dramatize the effect yielding mixed results. The final look of duotones tended to be more stylized than realistic, and while the method managed to bring a subtle beauty to some images, it most often looked like a gimmick added to attract attention, which is what it was.

Extra color could also be added to collotypes without the use of multiple printing plates. The plate would first be inked with a stiff black or a dark color ink and its surface wiped clean, but before it was printed it would be inked once again only this time with a more pliable oilier ink in a lighter color though usually of the same hue. Browns, sepia, blue and green were the most common colors used in conjunction with this method. The resulting image had less contrast and a more pleasant color cast. Unlike two plate duotones and heliotpyes there was no inadvertent overprinting of the image*rsquo;s highlights.

Postcard

Tritone Heliotype: The card above was produced from a single collotype plate, but it received ink from it twice; first printed with red ink and then again in a deep brown. The collotype texture is so fine that exact registration is impossible, and the final print shows off both colors. While tonal and color shifts are extremely subtle, it does seem to produce a richer image. In the detail below the red and brown wormy marks are identical, which shows that only one plate was used.

Postcard


Postcard

Tritone Heliotype: The single plate that produced this collotype postcard was first inked in black and then again in a lighter blue. Both colors were then printed simultaneously. This manner of inking developed by Ernest Edwards has been in use since the 1870’s



COLOR COLLOTYPE

As in color lithography multiple collotype plates could be employed to create a color image and they began being used this way in 1873. There were two different approaches to the way these multiple plates could combine color. One method was to treat each color as a solid tone; blues would print blue, greens would print green, and only in a few areas would they overlap. In most cases color was applied locally. With lithography overlays of transparent color splatter were routinely employed to create new colors but in collotype its small distinctive broken ridges of opaque color can only blend optically. This inevitably leaves much of the white of the paper exposed producing prints with greater luminosity than found in chromolithographs, but just as often the image could look excessively pale. While the subtlety of detail rendered was immense, the lack of color blending often created an artificial look.

Postcard

Color Collotype: This color collotype was printed with only three plates with minimal color overlapping.


In chromolithography, the positions for each color were traditionally traced off of a key drawing and then placed on a separate stone for printing. This could not be done with color collotypes since they are a completely photo-based process. Separate negatives needed to be made for each color used, all containing the original image but exposed differently to accommodate the needs of that particular hue. Lighter inks tend to loose definition when printed, so areas such as the sky needed to be exposed to print proportionally darker than the overall image. Printing high densities of marks to produce both value and color saturation often led to problems because they could not always be used for both qualities at the same time. Areas of high color saturation could compete for dominance with dark details and obscure one another if overlapped. All retouch work to remove areas not specific to that plate’s color had to be done on the negative before the image was transferred, which was often difficult to achieve where fine detail ran together. The very thin emulsions of collotype plates have no workable depth and details cannot be honed out as on a stone without destroying the image.

Postcard

Color Collotype: This color collotype was printed with four plates inked in red, yellow, blue, and black. While the pallet is similar to a tricolor print, and some attempt was made at achieving natural color, it is far from looking natural. It was most likely based on a black & white photograph because the distinct placement of colors seem to be divided by a retoucherÕs hand and not through photomechanical means.


Postcard

Color Collotype: While collotypes are renown for their ability to capture detail and render realistic looking images, this quality can be skewed when inked in a nonrealistic manner. Wild colors were sometimes chosen to match public taste, not reality.


Another approach to printing color with collotype was to use the entire palette in creating highly subtle hues and value gradations instead of localized color. Each plate was exposed to print an optically light image, consisting of dark but sparse marks that left much of the paper around them empty. When all plates made in the same manner were printed together, the resulting print contained a dense mixture of extremely small dots that produced a rich look like that found in gravure. Getting the right color balance with this method was a very difficult task, which rendered the process too expensive for most commercial printing. While this process was largely reserved for high end art reproductions, these types of postcards are no longer that popular because of our overexposure to color images makes them less unique.

Postcard

Color Collotype: The highly colorful Italian view-card above was printed from multiple color plates. Even under high magnification the overlapping specs and ridges printed from these plates renders the details shown below almost indecipherable.

Postcard Detail


Postcard

Color Collotype: While the richness of tone captured through collotype often translates into highly saturated images when printed in color, the subdued palette of the color collotype above is much closet to the look of a tinted halftone. Even so, there seems to be a peculiar richness to the image, which is caused by the dominance of single hues when rendering objects rather than through optical halftone blends. This trait and the collotype texture is more clearly evident in the detail below. Different looks can be achieved with color collotype, but some characteristics of the technique are usually evident.

Postcard Detail


Postcard

Color Collotype: On this Dutch collotype postcard, the brown plate was exposed to create a dense pattern of markings that would hold a maximum amount of ink, but it has obscured the darker lines of the blue plate where there is overprinting. The long detail below reveals how this type of printing that blurs color boundaries can adversely affect definition. This problem is similar to intaglio prints that are inked à la poupée.

Postcard Detail





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