I make mine from aluminum cans. They last virtually forever. The writing doesn't fade from the sun because it is an impression in aluminum made by a ball point pen. It can't fade. I have tried everything else (milk jugs, old venetian blinds, plastic knives, sharpies, etc.), but they all fade or crumble or both in our Florida sun. None of them last the way these do. Once you make a tag this way, you'll never replace it.

If the tag is going next to a plant in the yard, I hang it from heavy gauge wire. But if it is going into a potted plant, I skip the wire and just slip the aluminum tag against the inside rim of the pot about half-way into the dirt. For me, the tags don't need to be on "display" all of the time. They just need to be available in case I forget what the plant is.

Here are some instructions. I don't do the fancy backward writing shown in some of the links. I just write directly onto the front of the tag using a ball point pen in regular, readable writing. It works.

I also cut my strips the long way, from the top of the can to bottom of can, rather than cross ways, around the can. That way, the tags don't curl.

I use needle-nose pliers to bend the wire perfectly to hang the tags. I make sure the loop is all the way closed with about an inch overlap so that there is no way the tag can come off.

http://littlehouseinthesuburbs.com/2009/03/aluminum-can-plant-markers.html

http://tlc.howstuffworks.com/home/aluminum-can-plant-markers.htm

http://www.instructables.com/id/How-to-make-durable-plant-markers/

http://gardenerscott.blogspot.com/2011/04/making-aluminum-can-plant-tags.html

Have fun!
Carol

I use the white slats from cheapy blinds. One shade makes hundreds of perfect markers.

I've used most everything also with mostly 'only so-s0' results. I do have a label maker and the labels I've made so far seem to be holding up quite well attached to the backs of white plastic write-on labels I get from a lumber co w garden center where I can get the same bag for $2 that costs 5 elsewhere. That being said, I'd guess MN sun isn't even close to FL intensity. I also keep my eye out in the fall at the same store and stock up when they close out the labels. I haven't tried it yet but it would seem to me I should be able to 'clean up' labels I've written on with a light touch of a sander.
Oh my, lots of thoughts and way too little time - LOL
Will