solarise

verb

1. reverse some of the tones of (a negative or print) and introduce pronounced outlines of highlights, by exposing it briefly to light, then washing and redeveloping it
2. become overexposed"The film solarized"
3. overexpose to sunlight"be careful not to solarize the photographic film"
4. expose to the rays of the sun or affect by exposure to the sun"insolated paper may turn yellow and crumble"