Gouache on paper. Approximately 4x6 inches.
 
It was a lovely day at the beach. The tide was incredibly low, which made exploration of the rocks and tidepools into a beautiful adventure. Thousands of mussels, hundreds of starfish, and even a big piece of an octopus tentacle!  I did this piece as a demo for my student who wanted to know how I do back-lit scenes in gouache.