This one had more steps ("drawing" with the glue, covering the glue with salt, and touching a paint-loaded brush to the design) than most of our projects and also required a level of self control for the paint brush step. Some of the kiddos definitely painted and scrubbed with their paint brush. It was a fun project though and the end result is pretty cool. I think we'll try it again in a few months.
Here's Thalia's salty watercolor painting above and a detail of the painting below.
The paintings haven't dried yet. Apparently the reason you use matboard is that if you use regular paper they buckle and crack when drying.
Update: Here are the dried salty watercolors. Beautiful and sparkly!
Update II: We did the salty watercolors art project again when the kids were older. They loved it!