Now, this is a cool idea for portable art – taking a little mint tin and hot gluing it to an old watchband. Combine it with a water pen and there you have it! I’ll be making one of these…
One set of directions for using little Altoids metal boxes for a palette is here, you could adapt it to a smaller box easily. http://www.instructables.com/id/Altoids-Tin-Pocket-Sized-Watercolor-Box/
I‘ve also seen them done with a 3D printer insert – http://www.thingiverse.com/thing:753052
At our San Diego library, we have a 3D printer that can be used for FREE. Check your local library!