What ever you decide to use for working on clay , keep in mind you want
something that will not hold a lot of dust.
I really hammer in to the kids how we need to keep clay dust to a
minimum. After you use clay year after year and many times during the
year , I think it is good to be aware of the health factor. The mats
(individual) I use (oil cloth- over 10 years old) gets rinsed by student
helpers after we are done with the clay assignment (and that is six
times a year.) There are a lot of good suggestions out there. You might
try a few to see what works best for your kids.