Cross-polarising

Wet day - so a chance to play indoors. It's ages since I blipped a cross-polarised pic, so thought I could get away with one. A sheet of polarising gel placed on a lightbox, clear plastic forks and a polariser on the camera lens - shows up the stresses in the mouldings as rainbows. 

Thought I'd concentrate on the tines of the fork, rather than on the "fork 'andles" :))