My permanent labels are Dymo aluminum strip labels. You have to buy an industrial-quality Dymo label-maker (available for about $150, along with the aluminum and also stainless steel labels, which I haven't tried, from the A.M. Leonard company - they have a website) and order the tape by mail. My old tool is now worn out and I have to get a new one, but it produced more than a thousand labels before the "A" disappeared. I attach them with fairly heavy gauge galvanized wire pins. As insurance, I also bury a plastic label written on in soft pencil (which lasts longer than any ink) in the pot or next to the plant in the rock garden. If you bury a label it does not go as brittle as in sun. The extra information is on the plastic label, such as the seed source and year sown. These embossed metal labels are hard to read, especially at a distance, but they are absolutely indestructible and permanent. Jane McGary NW Oregon