If you punch the hole correctly they will last until I have filled up both sides with information, (several years). I do not try to erase them because they are so cheap to make. I also use a #2 pencil which will not fade for several years.
These are seedlings moved from the field to the hybridizing area and the information is written on a mini blind with a #2 pencil and will be there for a minimum of three years until I register the plant or destroy it.
