Here are the various types of labels I tried:
CNC-machine engraved painted aluminum. Best results, most difficult, most expensive. I use this for in-ground trees

Dymo embossed 1/2" black labels w/ 1/8" hole punched. Very good results, easy, cheap. This is my favorite for container plants, only the larger Dymo embossers can use this wider tape size.

Dymo embossed 3/8" colored labels w/ 1/8" hole punched. I lost a few of these because the 3/8" tape width doesn't leave much margin for error when punching the hole. If I get it even the slighest bit off-center it becomes a weak point and can pull off. I only used this because I had a multi-pack that came with a cheapo plastic Dymo embosser.

Emboss-O-Tags. These are cardboard sandwiched in thin aluminum. They are okay but I tend to botch the writing as you have to go slow and use a ball point pen. I end up using whatever pointy object I have nearby instead and they come out poorly. I wrote really slowly with a pen to make this one, usually they come out much worse for me. The visibility could be better and they tend to accumulate dirt and water scale. They cost more than Dymo tape but you don't have to buy the embosser. I don't use these anymore but the ones I created over the years have held up well enough

Cut aluminum cans emgraved with a sharp object. I really don't like these. Flimsy, sharp, crease easily, terrible visibility.

There are a ton of electronic printed labelmakers out there. I tried one briefly but got frusterated with having to put batteries in it and the usability was poor. This might actually be the best approach for a lot of people, though, especially if you make a lot of repeat labels where you can print multiple times. I don't have a lot of duplicates so using the manual wheel ones isn't really slower. Not sure what UV resistance is like.
If you got the emobossing route I strongly recommend buying a "vintage dymo" model 1570 or similar on ebay. I got one for about $35 and it is great. The brand new ones Dymo sells are either complete junk (the plastic $15 ones) or extremely expensive (the Rhino is at least $100)
