Loving this! A calendar that indicates the passing of days by ink absorbed by paper. One a day, the numbers are filled with ink until at the end of the month, the paper is full. Every month has its own color ink, representing the season. December for instance in blue, while spring is orange/red. (which in my book represents autumn actually) Unfortunately the calendar is not for sale, but was produced as a prototype for the London Design Festival. The design is by Oscar Diaz

Ink Calendar by Oscar Diaz