Boards
Like a snazzy tie on a seventies tv programme,
the hatch pattern on the drawing I'm working on is kicking out a right moiré effect.
http://en.wikipedia.org/wiki/Moir%C3%A9_pattern
So... tel me... what's your favourite optical illusion?
Mine is the Same Collour Illusion. Except I kinda hate it with a passion at the same time, cos I just can't force my eyes to see past it.