I am wondering if there is any type of chemical, when exposed to light, will transform from clear to black?

-- Ryan Semeniuk (rsemeniuk@yahoo.com), June 01, 2001

Answers

There are iron salts that are light sensitive. These iron salts are the basis for both cyanotypes, and platinotypes. A web search on these two terms should provide you with more information.

-- Joe Lipka (JoeLipka@compuserve.com), June 04, 2001.

Sorry not an answer but a question. Im really curious as to what you plan to do with it?

-- stephie d (stephie9000@hotmail.com), April 02, 2002.