Studio Sunday-Rock Plant ID for the Garden

I've been thinking about a way to name the plants in the garden for a long time. I thought about the traditional copper and aluminum tags but when I've seen them in gardens I find them jarring. I've played around a little with writing on rocks and decided that was the answer. I used acrylic paint thinned with acrylic flow medium and a brush. I've sprayed some with an acrylic finish and have two without to see how they hold up outdoors. I suspect the sprayed rocks will be better but I don't like the shine so I am going to look for a spray with more of a matte finish. I could probably brush on something but I prefer the convenience and speed of the spray.