The San Francisco Garter Snake is one of the most colorful of the garter snake family making it a great subject to paint. The size also is a good factor. I prefer my painted snakes to be around the actual size of the real live version. Of course that is difficult sometimes when it comes to adult constrictors. Garter snake sized rocks are plentiful where I live. Mid-sized rocks like the one pictured is also easier to maneuver than the ones I use for rattlesnakes or constrictors. Smaller rocks are easy to manage but more difficult to get good detail when painting the scales. I am about out of decent rocks these days. Luckily the weather is warmng up. I’ll need to go rock hunting again soon.