Making your own plant tags is easy. All you really need (as this garden video shows) is a large and sharp pair of scissors, an old yogurt container (or something similar) and a few minutes.
Do use a pencil or permanent magic marker on hese tags. I once made a mistake and picked up a water-soluble marker. Within 48 hours the humidity and watering had removed all the names from the seedlings.
Check out this garden video on making your own plant tags.
Make Your Own Plant Tags Easily and Cheaply