Received this question from Tina Cremer: "What is the best method to firmly attach the labels to the wall, yet not remove a chunk of wall when the labels are removed?"
Tina, when I worked in the museums, we honest to goodness used lots of rolled up masking tape on the back of our labels. And they lasted for the duration of our exhibits.
By the way, I mentioned this in a previous comment, but it seems important to do so here as well. I've seen labels printed on clear mailing labels, which never look good on the wall. The uneven wall texture (walls are rarely perfectly smooth) seeps through the label unevenly
and gives the label a strange multi-colored surface.