Petroglyph tiles

These are petroglyph "tiles", actually 4x4 and 5x7 pieces of textured clayboard for watercolor that I was asked about, so I will submit them here. I paint the background rock colors (usually three glazes) and then, when the last glaze is dry, I lift out the petroglyph shapes. I use any of my hundreds of photos I have of these things and try to stay as accurate as possible to the figures and shapes carved out of stone as they were done by the Ancients. I then "enhance" them a bit with some added black lines here and there, spray them with clayboard fixative and put them on the appropriate size display easel or table stand. I sell quite a few of them, stand included, and they have become quite popular. I thought originally I would mostly make the 4x4's, but people at my sales have been asking for specific figures to be done on 5x7's and 8x10's. These could also be framed, without glass, since they are sealed but I think they are nice to sit on a shelf or table since everyone is so limited on wall space for art, it seems. Someone asked me about using the smallest ones as coasters and since they are sealed that might work. However, I would not guarantee that since I haven't tried it and my original intent in creating them was for display.