I cut out a large mitten from card stock and used spray bottles (dollar store finds) filled with liquid watercolor and water to dilute it a bit. A little goes a long way. You could also use food coloring if you don't have liquid watercolors on hand.
Once the children had sprayed the watercolors to their liking, they sprinkled salt over their painting.
We let the salt sit on the mittens until they dried, then I shook them out. Some salt remained on the mittens but lots of it fell off, revealing some really fun effects underneath.
Between the spray painting and the salt our finished mittens had fabulous texture and wonderfully unique spots of color.
I love how they turned out.
Have you tried adding salt to your paintings yet?