Exposing Silver Nitrate To Light Turns It Which Color?

Non-silver and historic processes are general terms that refer to various photographic processes that do not contain silver in its emulsion or were popular around the plow of the 20th century. Invented during the latter one-half of the 19th century, these older processes include collodion wet-plate, van dyke brown, glue-bichromate, and cyanotype, amidst others. Each requires mixing and coating the emulsion by mitt. Hence, the resulting images accept a painterly quality, an effect frequently left from the brushstrokes in painting the emulsion and the small inconsistencies and inaccuracies that outcome from hand processing.

In the 1960s and 70s, inquiry into antique photographic processes unearthed descriptions of these techniques, which had not been in use since gelatin silver printing became dominant. It is unclear what led to this revival. Some accounts claim that photographers documenting Civil War reenactments wanted to subscribe to the same level of historic accuracy as the participants "fighting" the battles. Photography was also starting to gain greater credence as a fine art course during this flow and many artists were attracted to the experimental nature of celebrated processes. Revivalist practitioners rewrote the recipes for historic formulas from the language of the 19th century for a contemporary audience. The books and online sources in our resources guide describe the processes of making Van Dyke Brown, gum bichromate, cyanotype and other print positives.

Printing Facilities and Safety

Each procedure has specific needs and prophylactic requirements. The post-obit techniques are all contact printing processes; the size of the print will be the same size of the negative. These processes require an ultraviolet (UV) light source. Common sources are the sun, full spectrum or found growth fluorescent lamps, sunlamps and mercury vapour lamps. There are many variables to consider if making exposures with the sun, including consistency and intensity. While sunlight is readily available, information technology varies according to the fourth dimension of twenty-four hour period and year and the weather conditions. UV bulbs may ensure more consequent results. Other facilities and equipment needs are minimal. Working with solutions requires a dimly lit space.

Chemicals, specially dry chemicals and argent, may be toxic, crusade staining or burns and should be handled only when wearing gloves, goggles and a respirator. We provide details about chemical safety for cyanotype, but chemical and toxicity information on the other chemicals usually accompany the purchase of this chemical science, can be located at manufacturers' websites or tin can be found by reading the resources we recommend for Historic Processes.

Van Dyke Brown

Van Dyke or Brown prints have deep dark-brown tones characteristic of work past the 17th century Flemish painter Anthony Van Dyck, hence the name. The VanDyke Brownish impress process originated around 1840 through astronomer and chemist J.F.W. Herschel's research with iron sensitizers. The Van Dyke emulsion can exist applied to most kinds of newspaper and natural fabric and requires minimal chemical science and equipment. Negatives tin can exist contact printed onto the sensitized Van Dyke fabric. Once the emulsion is mixed, information technology tin concluding for several months in a dark bottle. Cloth that has been coated should be exposed and candy inside a day, although in that location are reports of waiting several weeks with minimal difficulty.

photo: Amanda Norenberg, Molecular #1, Van Dyke Dark-brown, white beeswax, paper, fabricated from paw-printed ortho-litho negative, 20"x16", 2006. Norenberg imagines a system of energetic cells connecting our souls to our bodies. To visualize these shapes, she photographs string and wire sculptures and prints the images in Vandyke on rice paper.

Gum Bichromate

Mucilage bichromate (aka mucilage printing or bichromate process) is a non-silver printing method that uses emulsion made up of a colloid (such every bit gum standard arabic or albumen) made light sensitive with a dichromate (such as potassium or ammonium bichromate). Once the sensitized bichromate is applied to a sheet of paper, a negative can be contact printed onto the newspaper. The combination of a colloid and a dichromate (also called a bichromate) is called a chromated colloid. Alphonse Louis Poitevin, a French chemist, is credited with discovering the light sensitivity of chromated colloids in 1855. John Pouncy, an Englishman, took Poitevin'south discovery and developed the mucilage procedure sometime between 1856 and 1859. The procedure reached its greatest point in popularity around 1900.

The uniqueness of the gum bichromate process lies in the addition of watercolor pigment, of whatsoever color, to the emulsion. While the color of other photographic processes, such as cyanotype, is a event of the emulsion's chemical reaction, a gum print's color is determined by the addition of pigment. Multiple colors, fifty-fifty up to CMYK full color printing, tin be produced by re-coating the paper several times between exposures. Printing with multiple colors is a more than elaborate process, requiring separate negatives for each colour used. Gum prints tin too exist brushed during the launder to add a sense of texture and a painterly effect. Cosmos of the epitome begins by press the negative and continues afterward with the possible addition of more color and brushwork. Gum bichromate prints have a soft and long tonal range without fine detail.

photo: Pierre Gour. detail of Man Drinking Milk. 2005. gum bichromate on canvas.

Collodion or Moisture-Plate Process

Collodion wet-plate negatives are fabricated with calorie-free-sensitive silver nitrate, unlike the silver chloride or silverish bromide mixture in contemporary gelatin-silver based photography. When exposed to lite and then processed, the emulsion in most photographic processes becomes visible and changes colour.  The collodion's argent nitrate turns black. The wet collodion procedure is meant for negatives, although the procedure can too exist used to make unique positives that cannot be reproduced.

photo: Shanna Nash, Drinkable-up, Jeff, wet-collodion negative printed on black-and-white fiber-based paper, 20x24", 2005. In its heyday, moisture-collodion portraits required long exposures. The effort of sitting still and the formal nature of portraiture meant that sitters posed with a direct, somber expression. In her sittings, Nash floods the scene with powerful lights. The shorter exposure times encourage her subjects to present gimmicky activities and expressions.

Collodion combined with silver nitrate is a light-sensitive coating; the collodion solution can exist coated on glass to make negatives or used in positive processes, such every bit ambrotypes and tintypes. In the collodion wet-plate process, guncotton, alcohol and ether mix to produce collodion, a clear and gluey fluid that dries quickly. Formulated in 1846, the mixture made a perfect liquid bandage for dressing wounds during the Crimean State of war (1854-56). Frederick Scott Archer reformulated the solution for photographic purposes in 1851. Collodion coated on a glass plate, sensitized and exposed, yielded a transparent negative that replaced the costly and irreproducible daguerreotype and the paper negative of the calotype. From the 1850s through the 1870s, the process was used for such diverse purposes as making negatives documenting the Civil War or elaborate scenes and portraits in the style of allegorical paintings.

Collodion negatives take the finest grain of any silver-based film and can exist enlarged to make big prints on contemporary silverish-gelatin newspaper without loss of detail. Images show fine texture and wide tonal range and, due to the emulsion'due south thick consistency, sometimes accept smooth streaks or bubbles. The moisture collodion process can likewise be used to brand a unique, irreproducible positive, known as an ambrotype. An ambrotype is essentially a wet-plate positive exposed with less lite (to be thin) and developed with diluted developer and placed on top of black newspaper or velvet. The black backing creates shadow areas, while the negative'southward silvery produces the highlight areas, resulting in a positive epitome. Ambrotypes have a ghostly quality similar to daguerreotypes due to the reflective glass surface.

The collodion wet-plate process

The wet-plate collodion process is not for beginners. Collodion is hazardous and explosive chemistry and it is reported that many early practitioners demolished their darkrooms or lost their lives due to careless handling.

Cyanotype

The cyanotype process is considered to be the simplest of all the historic processes. Information technology tin be used to make contact prints from negatives (the terminal image will be the same size as the negative), or photograms. Information technology is fe-based, just as the Van Dyke Brown procedure, simply characterized by deep blueish tones. J.F.W. Herschel discovered cyanotype's basic chemic components: potassium ferricyanide and ferric ammonium citrate.

While we recommend the traditional cyanotype process below, this "historic" technique is all the same evolving as practitioners seek chemic improvements or new artful qualities. For example, the  "New" Cyanotype process by Mike Ware is an updated process that offers an exposure time significantly shorter than the traditional processes and with less risk that the blue tone will rinse away in the "developing" stage. However, this new version is fairly difficult and toxic to prepare,  requiring careful attention to handling.  The traditional process is far less complicated to mix and prophylactic enough that Photographer's Formulary claims that children tin work with the working solutions of chemicals. Both the traditional and the new process tin be practiced using kits bachelor from Photographer's Formulary. A detailed process is available at www.photoformulary.com/uploads/07-0090.doc.

photograph: Toby Millman. Tribute to Sakhnin. 2005. Cyanotype. The Sakhnin soccer team, with a squad of 12 Palestinians, seven Jewish-Israelis, and 4 foreigners, is a symbol of coexistence. With the smallest budget in the Israeli premier league and the least support, the team even so managed to win the Israel State Cup in 2004. In her Tribute to Sakhnin, Millman used the cyanotype process to juxtapose a photo of a soccer field with a line etching that resembles a design of a house. Each programme symbolizes borders, motion and homeland.

Tools, materials and equipment

• Cyanotype kit from Photographer's Formulary (model #07-0090, includes instructions and all necessary chemistry)
• a negative (for contact printing) OR an object (for a photogram)
• heavyweight acrid free paper (extra paper for test sheets)
• a bristle OR foam brush
• 2 dark chocolate-brown storage containers (with a chapters of 500 ml)
• several small beakers OR measuring cups for mixing
• mixing spoons
• a dropper for measuring ml
• sunlight OR a UV light source (the Cyanotype kit recommends a General Electrical 275 or 300-watt sunlamp, but any UV calorie-free unit will work)
• a contact printer OR sheet of glass
• water (for best results, distilled water is recommended)
• optional: a dark container with a capacity of 100 ml (for Potassium dichromate which can exist added to a working solution for high dissimilarity printing. Information technology is included in the kit from Photographer's Formulary and is described in the kit'due south instructions)
• optional: a hairdryer with a absurd setting (to speed drying fourth dimension)

Safety and handling

While Potassium ferricyanide contains cyanide and could crusade irritation to the pare, it's toxicity for chronic wellness concerns is non known. Potassium dichromate is both toxic and an oxidizer. To dispose of excess solid potassium dichromates, e'er launder the solid downward a bleed with abundant amounts of water. Never dispose of the solid in a wastepaper basket. Spillage of a dichromate solution on the pare will crusade a chemical burn, which volition appear as ulceration. In addition, all chromium salts are potential carcinogens. Wear disposable condom gloves when handling this compound or its solutions. Make clean all trays and containers thoroughly with soap and h2o.

Printing-Out Newspaper

Invented in the 1880'south to supersede albumen papers, Printing-Out Newspaper has a rich tonal range, an historical color palette (red-browns that tin can be toned towards dark purples), and the ability to exist sensitized by the sun. Printing-Out Paper (also referred to equally P.O.P.) is a contact-press procedure which, due to its devoted following, is nonetheless in manufacture and available through distributors of photographic supplies. (SUGGESTED READINGS/Resource/GLOSSARY spider web-2 HERE)

As the P.O.P. darkens during the exposure process, night areas of the print block additional lite from hit the newspaper: this self-masking allows lighter areas to catch up. In this way, Printing-Out Papers automatically, internally, adjust their own contrast. During exposure, the P.O.P. image may be monitored to check its progress - for this reason, a split-dorsum printing frame is recommended.

After exposure and a quick water rinse, the P.O.P. may exist toned towards a chocolate-chocolate-brown or a absurd eggplant hue, or kept at its (untoned) orangish colour. The manufacturer recommends toning with an Ammonium Thiocyanate / Gold-Chloride solution (included in Chicago Albumen Piece of work'due south P.O.P. starter kit), although the Ammonium Thiocyanate may be substituted with other chemicals.

Next, the newspaper must be stock-still with plain hypo (Sodium Thiosulfate) or a hardening fixer such as Kodak Fixer (also included in the starter kit). Do not utilize a rapid logroller, which will bleach Printing-Out Newspaper and ruin the print.

Finally, clear the hypo with fixer remover, wash, and dry the print. Flatten the dry out print.

photo: Charles Fairbanks. Tell Better Stories (after Timothy O'Sulivan). 5"x7". Press-Out Newspaper print. 2006.

Press-Out Paper should be refrigerated or frozen for long-term storage, merely tin exist stored at room temperature (effectually 70˚ F or 21˚ C) for up to a year.

Historic Processes Resource

BOOKS:
Christopher James, The volume of culling photographic processes (Clifton Park, NY: Delmar Cengage Learning, 2009), 2d edition.
John Barnier, Coming into Focus: a step-past-footstep guide to culling photographic printing processes (San Francisco, CA: Chronicle Press, 2000).
David Scopick, The Gum Bichromate Book: non-silver methods for photographic printmaking. second ed. (Boston, Mass.; London : Focal Press, 1991).
Bea Nettles, Breaking the Rules: A Photograph Media Cookbook, tertiary edition (Urbana, Illinois: Inky Printing Productions, 1992). Includes recipes for Cyanotype, Van Dyke Brown Printing, Gum Bichromate and others.
Mike Ware, Cyanotype : the history, science and art of photographic printing in Prussian blue (London : Scientific discipline Museum ; Bradford [England] : National Museum of Photography, Movie & Idiot box, 1999).
Lyle Rexer, Photography's Antiquarian Avant-Garde: the new moving ridge in quondam processes (New York: Harry N. Abrams, 2002).
Jan Arnow, A Handbook of Alternative Photographic Processes (New York: Van Nostrand Reinhold, 1982).

INTERNET:
Alternative Photography
Manufactures, recipes and technical data well-nigh culling photography processes.
http://www.alternativephotography.com/
Photographers' Formulary
A source for chemistry, nonsilver processing kits, supplies, technical back up and workshops.
http://www.photoformulary.com/
Rockland Colloid Corp.
A source of nonsilver processing kits.
http://www.rockaloid.com/
Bostick & Sullivan
A source for camera equipment, chemistry, books, and other technical information.
http://world wide web.bostick-sullivan.com/
The Earth Journal of Mail service-Mill Photography, Issue #1, 1998
downloadable at http://world wide web.alternativephotography.com/

Printing-Out Paper Resources

SUPPLIERS
For P.O.P. in the United States, contact the Chicago Albumen Works
world wide web.albumenworks.com

Source: https://www.reframingphotography.com/content/non-silver-historic-printing-processes

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