Maybe for Charlote's Web (?) Water color crayon resist artwork, an Original watercolour painting by Kirsten Bailey, but could be adapted for a children's art activity. Great for a fall wall hanging or spider picture for the fridge!
Watercolor tree art project, great for very young kids--adult places masking tape in pattern of a tree, kids paint over as much as they want. When you remove the masking tape, a tree is waiting underneath!
popping paint filled balloons on a canvas . put paint tape to cover the place to stencil, put paint filled balloons around canvas, pop with darts (slingshots?), let dry, use stencil to add silhouette - love it! Or do the crayon melting thing!