This is inspiring! When I can, I'm going to get some of the stuff used here to make tags like this. Thank you so much for sharing a brilliant yet inexpensive and fairly attractive solution to this common problem.
I don't have a plant budget this month and need a cheaper (repurposed/recycled) tag to help me remember which color of holiday cactus is which for trading later, before the last of the blooms finish. I cut an aluminum soda can into little pieces and writing on them with a ball point pen engraves them very well (but the particular pen I used didn't leave any ink.) I put them on a soft, puffy stack of ads from the newspaper so the gouges would be as deep as possible. I should poke holes in them and attach a paper clip to stick in the soil at the base of the respective plants, but I may or may not end up being that complete, I know how lazy I am. Sticking between plant and pot edge is probably their final destination.
Oh, and these pieces I've cut have sharp edges. I think I'm going to put my leather gloves on before making the rest of what I need. I've already tempted fate enough and don't want a giant "aluminum paper cut." Please don't cut yourself on behalf of my cheap-o suggestion!