One of the easiest places to find it is at a pottery supply place, that has clays and glazes. It should be dirt cheap, somewhere around $1/pound. Shipping gets expensive.

If you ask for chalk and the clerk looks blank, be sure to offer its other names:  calcium carbonate and whiting.

And if they don't have it but know what you're talking about, be sure to ask if they know where you can find it locally.

Here are some places in MI (mostly Detroit): http://www.magicyellow.com/category/Art … it_MI.html

Sue

Thank you both.  That is awesome information!