How to build a portrait with dice
elusivesnark.com
elusivesnark.com
http://www.attackofdesign.com/how-to-build-a-portrait-with-d...
So the back side of that portrait would have sixes in place of ones, and so on - generating a negative, with black taking the place of white, and white taking the place of black.
But seriously, 2560 dice => 17gram 16mm-size dice. That's very heavy dice for their size. I would have expected less than a quarter that!