We found a lovely website that has a different project to sketch every tuesday.You send in your pictures which are then put in a slideshow. This weeks theme was bubbles. Heres Corys picture. He remembered a nature program we watched ages ago about the spider who lives on the surface of the water and collect air bubbles that they floats about the surface of the water in.
the link for sketch Tuesday is
http://harmonyartmom.blogspot.com/p/what-is-sketch-tuesday.html
