http://www.invurt.com/2011/07/15/sunshines-top-ten-july-2011/

The artist uses a canvas that is imbued with a hard to find hydrochromatic ink sourced from overseas, that changes from white to blue when it gets wet. Water is sprayed onto a stencil and a blue image appears which evaporates. After 15 minutes, the canvas returns to its’ original white state, so the image [...]