Our Master Gardener's group uses 1" wide labels, so you can fit lots of info on there. Last year, for one of our demonstration beds, I used ink-jet address labels to print my plant information on. I affixed each address label to one of the plastic labels, and covered them with clear packing/mailing tape. The labels held up all summer, even through all of the rain we had. I was able to save virtually all of them for reuse this year.
I also like the P-touch labels, and just used them for the first time in my garden last year. I affixed the P-touch labels to the metal garden stakes. So far they look great. I was able to find the industrial-strength P-touch cartridges, so they should hold up better against fading and weather. For my seedlings, I use 4" plastic labels marked with a Sharpie--inexpensive and quick. Will have to look at the paint-pens at Michaels.