Last year I used spackle to coat my kids 3-D sculptures. It worked quite
well. They put on vinyl gloves from the nurse and slathered it on with their
hands in the small spaces, and used spackle knives to smooth. They liked the
textured look better. All they did was press and pull straight up with their
gloved hands, fingers tight together, and it made very nice rough texture.
We left them white. Underneath we used foam core board, tag paper and
masking tape to hold it together. I was quite pleased with the results and
so were they.