“We’ve become accustomed to taking digital photos, but at the expense of creating physical prints. So I thought that it would be pretty great if our smartphones could be used in a creative way to fill this void. After a lot of experimentation, I discovered that older photochemical processes could be modified to fit our cellphone’s display. Traditionally these processes would use a method called “Contact Printing,” by which a film negative or piece of acetate/polyester containing a negative image would be placed on coated paper. After exposure to Ultraviolet light (sunlight), a positive image would be formed. Our phones don’t emit UV light, but they do emit blue light, which is close. And as it turns out, by modifying one of these photochemical processes (The Kallitype), you can make a photochemical piece of paper that’s sensitive to blue light! And thus, sensitive to your smartphone!
You will need the following:
- Dim Tungsten Lighting, or (ideally) Red Lights. Red christmas lights will work great!
- A clean, dry painter’s brush. Try to use smaller sizes so as to better control how much chemistry you use.
- Cotton Rag Paper, sometimes referred to as watercolor paper.
- Glass container or shotglass. It’s important you don’t use it for food or drink.
- Silver Nitrate, 12% solution. This can be a bit expensive. You can buy silver nitrate (powdered) from Bostick and Sullivan: http://www.bostick-sullivan.com/cart/60/200/. If you want to save time from making your own solution, Bostick and Sullivan offers this bottle that just needs warm water to mix: https://www.bostick-sullivan.com/cart/12-silver-ni… If too expensive, you can get away with this less concentrated bottle: http://www.bostick-sullivan.com/cart/634.html.
- Ferric Oxalate, 20% solution. Please just buy this readymade solution from Bostick and Sullivan to save yourself the trouble of mixing it yourself: http://www.bostick-sullivan.com/cart/153.html — It’s annoying to mix, trust me_
- Sodium Citrate Developer: https://www.bostick-sullivan.com/cart/147.html — This stuff “develops” the image on your print. You’ll get the best quality with this one.
- Fixer. This stuff makes your print permanent and cannot be skipped! Sodium Thiosulfate Crystals that can be bought here: https://www.bostick-sullivan.com/cart/433.html along with Household-grade Ammonia: http://a.co/1aXkC0R
- Citric Acid. While this can be bought in a variety of places and is food-safe, I recommend buying it through Bostick and Sullivan for purity (to group it into one order): https://www.bostick-sullivan.com/cart/107.html
- Nitrile Gloves. While nothing in this process is toxic, you don’t want to accumulate silver in your body, so wear these for protection.
_While the 10% solution works, your exposure time for making a print will be much longer and you should really double coat (coat the paper once, then coat again after 8 hours of drying).”