Sculpey Plant Markers?

I'm considering various ways to make somewhat permanent plant markers, seeing how the "permanent" marker on mini-blind slats faded to nothing over the winter! I'm still trying to remember what some of these perennials are!

If I were to roll out Sculpey and cut markers from it, how durable would the results be? I was thinking of writing the plant names on the unbaked clay, embossing it, then baking it. I could either make little tags, which would hang from wire stakes, or long narrow stakes I could just stick down in the ground. I like the thought of the dangling markers better, though...

My question is, is Sculpey weatherproof enough for this type of use? If so, how thick should I make the markers, and what, if anything, would I need to use as a sealer?

Thanks for your help, you smart crafters, you! :oD