Moon sand is the best craft I have found. It is not messy, and will not clump when wet. I love this for small children. My kids would play for hours on end with moon sand. It is easy to pick up so messes were easy to maintain. The shapes they would mold would hold well enough together that they could play with them like toys. They could make people and houses. They made a little car type thing to transport their people they molded. This really got them thinking about what they could build. The only down fall is it mixes just like play dough And turns a gray color. I would strongly recommend this to others, especially daycares and schools . It doesn't dye hands the color they are playing with and it is very easy to pick up.