Have you ever used these with kids? They are A-MA-ZING! The control of a pencil combined with the beauty of watercolors. We have been big into them around here the last couple weeks, using them for all sorts of things. Caleb did the background for his report on sea snakes with blue watercolor pencil and then after it dried drew the snakes on top. Both Kylee and Caleb have experimented with the science puzzles, tracing and coloring in watercolor pencils and then painting with water.
We only use the Crayola ones for now (between a dog and a kid that chew anything it seems like the better financial option) but there are also more professional ones that are not terribly more expensive if your family can care for them nicely!