The annual report for Podravka, a Croatian NOV 15 2007
The annual report for Podravka, a Croatian food company, has to be heated in the oven before you can read it.
Called Well Done, the report features blank pages printed with thermo-reactive ink that, after being wrapped in foil and cooked for 25 minutes, reveal text and images.
Well done, indeed. (thx, judson)