Re: Air-dry clay or unfired ceramic clay
In my experience, air dry clay is quite a bit more durable than unfired ceramic clay. Ceramic is more fun to work with but unfired pieces are generally pretty fragile. It can be rewet but I'm pretty sure once air dry clay is totally dry, it's dry. I think you probbly could paint unfired ceramic clay, but it absorbs moisture like crazy so I'm not sure how that would end up working out. I think this may be a case of deciding whether you want the kids to have the most genuine clay experience possible, or if you would prefer them to have something to take home that has a better chance of survival. Honestly I haven't used any clay in a couple years, but my opinion is that kids don't care how genuine their experience is. I'm biased toward natural clay but clay is always fun and as a kid I always wanted to have something to take home that would last, so without a kiln I feel like air dry clay is your best bet. It still comes in natural colors and you can add water to keep it soft as long as it hasn't completely dried.