HPS Students Make Sun Prints
During our third workshop students learned about first inventors of photographic processes and discussed what it means to invent and innovate. We also made sun prints using cyanotype paper. Cyanotypes one of the earliest photographic processes that makes blue images (the same blue as architectural drawings).
Sun printing is a photographic process that uses iron salts suspended on a piece of thick watercolor paper. When placed in the sun with objects on the paper, the areas that the sun strikes are chemically changed and adhere to the paper. After the exposure is made (5-20 minutes depending on how bright the sun is) the sun print paper is rinsed in water which causes the unexposed iron salts to wash away and the exposed iron salts to oxidize and turn blue. Making sun prints is a lot like a science experiment with some trial and error, and lots of observation of what works and what does not work.
Here is a link to more information about how sun prints work… http://www.sunprints.org/how-it-works/
