3M Safety Walk Slip resistant tape (clear) Found it mentioned on this Board. It was not easy to find. Home Depot website said it was at 2 of my local stores. Was Not. Got it from Amazon. Little Pricy but it works. You do not need big pieces on the rulers - I cut 1/4" wide pieces. It was suggested that you use a utility scissors and keep it for this application only. I got scissors from the Dollar Store - worked great. It is basically cut, peel of backing, stick on back of ruler.