Painted this one a few weeks ago on graph paper. It certainly didn't take watercolor the way illustration board does, but the squares were fun :) I also painted with a 99¢ kids watercolor set (Side note: hit "option" and then the number 4 if you ever want to make a cent symbol on the mac). See if you can find the spot where I ran out of the color I was using for the squares and had to mix up a new one that didn't quite match.
I'm realizing more and more the relaxing nature of tedious work. i.e. the boxes. It's like you go into your own little world while doing it. It's fun, give it a try.