One of the classes I’m taking this semester is called Contemporary Photography, a class where we learn lots of alternative printing processes (same class I made Mr. Pinhole for). Well, I was recently assigned to teach and give the class a demonstration on the Salted Paper Process, or salt prints. I figured, why not share this information with all of you? (So, you might read through this and think that it’s totally boring, and that’s ok. I just thought there might be someone out there who is interested in alternative printing processes and would find it useful. I won’t be offended if you don’t read through the whole thing ;) haha) It’s actually quite simple, and something you can do from your own home! All it takes is a little table salt and a few chemicals…
First Step: Making the Salt Solution. You’ll need Sodium Chloride (aka table salt), distilled water, a glass rod, some sort of heating tray, containers for the measuring and mixing the solution, a tray or pan to pour the finished solution into, and the paper you will be printing on.
- Fill the hot tray with water and turn the heat on.
- Measure out 500 mL of distilled water and 10.0 g of Sodium Chloride.
- When water is near boiling, put a container into the water and pour the water and Sodium Chloride in.
- Mix together your distilled water and Sodium Chloride with a glass rod.
- After the salt has completely dissolved, pour it into a tray.
- Totally submerse the paper into the tray, flipping it over several times until its completely wet.
- Hang to dry.
Second Step: The Silver Nitrate Solution. You’ll need Silver Nitrate, distilled Water, a glass rod, heating tray, containers, an eye dropper, the dried/coated salt paper from Step 1, a glass plate, tape, and scissors.
SAFETY PRECAUTIONS: Silver Nitrate is a really dangerous chemical. Don’t do this where kids could get into it, and be sure to take protective measures. Seriously, if you’re not careful, it could blind you or burn your skin. I’m not telling you this to scare you, because as long as you are careful and respect the chemical for what it can do, you’ll be just fine. But you should really use gloves and goggles during this part, and avoid contact with eyes and skin. (This is my cheese face.)
- Measure out 10 g of Silver Nitrate and 100 mL of distilled water.
- Warm the water in the heating tray like before.
- This next part is the tricky part. From here on out, you need to do the rest in the dark, or if you have a red light, a place where the paper will not be exposed.
- When water is warm, GO INTO THE DARK. It is imperative that from this point on you do everything in the dark, as the solution you are making will be light sensitive.
- Once in your darkroom, mix water and Silver Nitrate together with a glass rod until dissolved.
- After your solution has been made, take your fully dried and coated salt paper, and tape it to the glass plate on all four corners. (This doesn’t have to be done in the dark, as long as the solution stays in the dark).
- Take your paper, the glass plate, and the eye dropper into the darkroom.
- Get some solution in the eye dropper, and make a line across the top of the paper with it.
- Immediately, use the glass rod to softly run the solution over the entire piece of paper.
- Switch directions and continue as necessary, applying more solution if needed.
- Another option is to use a foam brush, which will give your picture a textured look from the brushstrokes, as opposed to smooth from the glass rod.
- Once the paper is evenly coated, lay it out to dry, still keeping it in the dark.
Third Step: Exposing the Paper. You will need your coated paper from Step 2, the negative you a planning to use, a glass plate, sunshine or another strong UV light source, and tape and scissors. (Sorry I don’t have any pictures for this section, as I did mine all in the dark…)
- There are actually several options for exposing your paper, including UV lights and actual sun exposure.
- I used a UV bed that we have my school, but direct sunlight works the best.
- Take your completely dried paper, and place it onto the glass, coated side up.
- Place the negative on top of the paper, emulsion side -the duller side- down (making it emulsion to emulsion).
- If desired, you can tape them into place to ensure proper registration.
- Once secured, take your materials outside into the sunlight or to whatever light source you are planning on using.
- Exposure times will probably never be exactly the same. Different factors (strength of light, contrast of negative, etc.) make it difficult to know exact times. You will have to experiment.
- But a good way to know it’s done is when it becomes difficult to see the image, because of the darks of the negative (where the sun is not shining through as much) and the darks on the paper (where the sun hit and the final image will be dark).
- Also, keep in mind that you will need to expose the print to look much darker than how you want the final product, because it will lighten significantly during washing and fixing.
Fourth Step: Rinsing and Fixing. You will need Sodium Thiosulfate, Sodium Bicarbonate or Ammonia, distilled water, and a few trays. (I would actually suggest mixing up these solutions while you wait for your paper to dry after Steps 1 or 2).
- Mix together 1000 mL of distilled water, 100 g of Sodium Thiosulfate, and either 2 g of Sodium Bicarbonate or 2 mL of Ammonia. (I used Ammonia). This makes your fix. Pour it into a tray.
- Once the fix is made and in a tray, fill two more trays with water.
- After the print is exposed, put it into the first tray of water for about 15 mins. This is to get rid of all the unexposed silver. You will actually be able to see the extra silver coming off.
- After the initial rinse, move your print over to the fix. Only leave it in for about a minute. This is enough to fix it, and the longer you leave it in the lighter the picture becomes.
- Finally, move your print to the third tray of water and leave it for about half an hour, to wash off any and all extra chemicals.
- Hang it to dry.
- You’re all done!
That probably seems like a lot. But I promise it’s really easier to do than it is to read. And that was just the most basic form of salt printing. You can also size the paper (dipping it into a gelatin solution before the salt solution) and that will give your picture a lot more contrast. You can tone your images, too, which will give them a different coloring than just a regular salt print. If you’re interested, here are a few common recipes…
A few alternative salting options: Gelatin Salting- Mix together 8 g gelatin, 18 g sodium citrate, 20 g ammonium chloride, 1000 mL distilled water. Fauver’s Gelatin Salting Formula- Mix together 20 g citric acid, 20 g, Kosher salt, 4 g Knox gelatin, 1000 mL distilled water. Both of those include sizing and salting in one, so you technically skip a step and have nice and contrasty pictures!
A few toning options: Gold-Borax Toner (warm/reddish color)- Mix together 800 mL distilled water at 100 degrees, 6 g borax, 12 mL 1% gold chloride solution. Palladium Toner (reddish-brown to slate gray)- Mix together 450 mL distilled water, 2.5 mL sodium chloropalladite (15% solution), 2.5 g sodium chloride, 2.5 g citric acid, Distilled water to make 500 mL. Platinum Toner (warm brown/gray/yellow)- Mix together 450 mL distilled water, 1.5 mL potassium chloroplatinite, 2.5 g citric acid, 2.5 g sodium chloride, Distilled water to make 500 mL.
So there you have it! Here is the print I will be turning in. I sized it and salted it separately, and used a gold toner on it. (Although scanning never does it justice..) Fun stuff :)