I've been painting on large garden stones for a long time now.  After a while I started calling them "garden and hearth" rocks ( stones ) as people would tell me they hated to put them outside as they were too nice.  So I'd tell them if they had a fireplace they could put them on the hearth and supply them with a stand.  

one of the hearth rocks

Some are obviously for gardens and I assure them that if they give them a good protective spray every two years and bring them in in the winter they would do just fine outside.  Most of the large garden rocks I paint on are slate.  They are the most interesting as they have irregular edges and different levels to them. I love working with those.  I try to use the different levels and edges within the painting such as the stone below.

The flower follows the conture of the stone.

As I ususally do with all my stone, I turn them over and this way and that to find the best way to put the image on it that I want to paint.

Some stones suggest an image right away, like the following stones.

Because of the size and weight of these stones I can only sell them locally unless someone is ready to pay for the shipping.  I haven't offered them for sale in my Etsy shop because of that.

I intend to have some painted for my booth at Artisan's Northwest, here in Thunder Bay, Ontario, Canada, next fall.  Although I may have to go rock hunting!