Nestor White who sells crinum and other plants on ebay as BulbsNMore sells tags made from aluminum cans which are easily imprinted/indented using an old ballpoint pen or stylus. He sells the tags with a punch hole and a length of heavy aluminum wire which can be used several ways including as a stake. So, since the writing is not ink/paint/pencil it won't erode over time. and aluminum is fairly corrosion resistant. Randy.R