Dutch photographer Rohn Meijer takes old negatives from past shoots and places them in a caustic chemical bath for months at a time. What he pulls out are negatives forever transformed, if not totally destroyed.

“Sometimes I find that nothing is left because they’ve disintegrated, and sometimes I’m pleasantly surprised,” he says.

The idea for the project came after Meijer discovered a batch of slides in his basement that had been exposed to moisture for 15 years. Most people might have tossed them, but Meijer saw that the moisture had created a pleasing crystallized effect, so he decided to experiment. He began developing a cocktail of water and other chemicals — a formula he prefers to keep secret — that would interact with the silver nitrate on the back of the negative and enhance the crystallization. To keep the negatives as saturated as possible, he built a homemade, hermetically sealed container for them to stew in.
The element of surprise is a distinct part of the process, but Meijer says he sometimes purposely applies his cocktails like paint to specific parts of the negatives to help draw out or accentuate different visual effects.

Source: Wired.com