so, what is all of this anyway?
It's art, it's cooking, it's science, and, of course, it's a bit of dumb luck.
Henry Fox Talbot (1800-1877) invented the salted paper process in the 1830s. Salted paper is known for its extensive tonality: it can print both the darkest tones and the lightest tones without losing detail. The key players in a salt print are silver nitrate and salt. If you've got salt and some silver nitrate laying around (as one does), you can make a salt print.
A salted paper print starts out with a sizing agent that contains salt. You can soak the paper in a plain salt water solution, or you can add in gelatin, ammonium caseinate, or carrageenan— basically anything gelatinous in texture. This gives the print different tonalities and finishes, from ruddy and matte to purple with a slight sheen. Once the paper is sized, it's coated with diluted silver nitrate. Silver nitrate is conveniently not light sensitive until it hits an organic (i.e. salt and those aforementioned gelatinous materials). So, salt and silver nitrate come into contact and create silver chloride, and you've got yourself a photographic substrate. Once the exposure is complete, the print goes through a series of seven baths (salt water, plain water, alkaline water, and fix are all you'll need).
Salt is wonderful in its simplicity, but the process is only simple on paper. There's a lot of troubleshooting involved in salt in every step. You're Hercules and salted paper is Hydra, except there's no golden sword to put an end to the multiplying heads. It's a lot of trial and error (or, alternatively, dumb luck).
The links at the end of this section contain various forms of salt prints. Lessons in Salt contains practically everything I've done with salt since Christina Z. Anderson taught me in 2016 (by the way, if you haven't noticed yet, Anderson is the root of all of this. I can take credit for my mistakes, but I can't take credit for the foundation. I didn't just wake up one morning knowing how to pronounce mordançage). American Mythos is solely gum bichromate over salt, Riptide Nostalgia is a series of hand-colored prints, and From Where They Came is my first foray into salted paper.
Salted Paper Printing: A Step-by-Step Manual Highlighting Contemporary Artists by Christina Z. Anderson
Photographer's Formulary salt kit | this kit contains everything you need to get started in salt. It's not as cost effective as buying chemistry in bulk, but it's the perfect place to start.
Photographer's Formulary bulk chemistry
Sodium carbonate (alternatively, you could use washing soda)
Items you can purchase on Amazon
Carrageenan (kappa carrageenan is seaweed based)
Connoisseur brushes (I use a 3 ¼" brush to coat silver nitrate)
Items you can buy in a grocery store
Diamond Kosher Crystal Salt (you can read about other salts I've tried under Lessons in Salt)
Distilled water
Washing soda
Papers I use for salt
Hahnemühle Platinum Rag (can be bought on B&H, Freestyle Photo, Adorama, Amazon)
Masa
Gum bichromate was developed in the late 19th century. Through the process, you essentially create a watercolor photograph. Gum and salt are at opposite ends of the alt process spectrum— where salt is regimented, gum is carefree; where salt is merciless, gum is forgiving. You can almost always save a gum print.
Gum, like salt, starts out with a size (I personally use PVA). Sizing the paper keeps the dichromate/pigment mix from sinking into, and staining, the paper fibers. Once the paper is sized, it's coated in a 1:1 mix of ammonium dichromate and a gum arabic/watercolor pigment mix. After a short exposure, the print is washed in plain water for anywhere from 30 minutes to one hour. This process is repeated for every layer. You're "painting" on a photograph, layer by layer. Each layer is its own color, the most common being cyans, yellows, and magentas. Different pigments will yield different tones, different tones evoke different sensations. For Land of Origin I used natural powder pigments, which are much more subtle than the vivid pigments I used for The Valley.
Additionally, gum can be printed over a cyanotype or a salt print. Cyanotype brings in cool, shadows, whereas salt brings in warm, historic shadows. American Mythos is entirely done in gum over salt, and select prints from The Valley are done in gum over cyanotype.
Sometimes you'll pull a gum out of the wash on its third layer and it's the most pristine thing you've ever seen, other times you'll be trudging through layer eight or nine with no end in sight. No two gum prints are the same.
Gum Printing: A Step-by-Step Manual, Highlighting Artists and Their Creative Practice by Christina Z. Anderson
Gum Printing and Other Amazing Contact Printing Processes by Christina Z. Anderson
Photographer's Formulary bulk chemistry
Gum arabic (liquid— gum arabic can also be found in a powder form and crystals)
Items you can purchase on Amazon
Gamblin PVA (comes in 8oz or 32oz)
Connoisseur brushes (hake, taklon, and bristle brushes are what I use)
Papers I use for gum
Hahnemühle Platinum Rag (can be bought on B&H, Freestyle Photo, Adorama, Amazon)
Fabriano Artistico, hot press
Twinrocker handmade paper (an expensive choice, but they have beautiful papers)
Cyanotype is arguably the most readily available alt process to practice. It only requires two main chemicals, ferric ammonium citrate and potassium ferricyanide. The process gets its name from its characteristic blue hues and its entwined history with architecture. Blueprints were traditionally reproduced with the cyanotype process, as the it was often not seen as a fine art photographic process. Cyanotype can certainly holds its own, though— when a suitable image is printed in cyanotype, it sings.
To create a cyanotype, start by mixing 10% solutions of ferric ammonium citrate and potassium ferricyanide 1:1. Coat your paper with the 1:1 mix, and let it soak into the paper for 10-20 minutes, depending on the humidity of your workspace. Once the paper has air dried, you can take a blow dry it (you just want to make sure that the chemistry soaks into the paper and not on top of it). Like any other alt process, cyanotype exposes under UV light. When the exposure is complete, the print will go through two baths: diluted citric acid (½ tsp for 2000ml) and plain water.
Gum Printing and Other Amazing Contact Printing Processes by Christina Z. Anderson
Photographer's Formulary bulk chemistry
Items you can buy elsewhere
Hydrogen peroxide (the best value would be at a beauty supply store, i.e. Sally Beauty)
Papers I use for cyanotype
Hahnemühle Platinum Rag (can be bought on B&H, Freestyle Photo, Adorama, Amazon)
Ah, the wildcard. Chromoskedasic sabattier (chrō-mō-skĕ-dă-zĭk să-bă-tē-ā)* is a darkroom process. Chromo prints get their characteristic metallic sheen from the silver particles plating out in silver gelatin paper. The process starts with a developed— but not fixed— silver gelatin print. Once a print is developed, it's placed into an activator and then a stabilizer. The print can be brought out into room light at either of these steps. Subjection to room light will create different colors, but it's essentially random. In person, a chromoskedasic sabattier can be incredibly metallic: golds, coppers, silvers, greens, purples, pinks, and blues can appear in a chromo print (of course when they're scanned, they often appear dull, and not all of the colors will be visible).
*I dutifully tried to give you an accurate pronunciation of chromoskedasic sabattier, I promise.
Experimental Photography Workbook : A Manual of Analog Black & White Darkroom Practice by Christina Z. Anderson
Items you can purchase from Freestyle Photo