I finally used this tip this year to mark some varieties of adeniums. It worked wonderfully! It's one of those tips that have been around for a while & when I finally get around to using it I wonder why it took me so long.
I actually had to buy a small mini-blind from the dollar store. The recycle store didn't have any, nor the 2 "goodwill" type stores I went to. But for about $5, I have enough plant markers to last for years!!