For the tactile characters, use appliqué with top-quality adhesive. Remove the plaques from the engraver immediately and weed away the excess appliqué. Then, run the finished plaques through a small cold laminator, which ensures that there are no “holidays” or spots where the character is not fully adhered to the plaque.
Let the plaque cure before you install it, and you won’t be embarrassed by characters falling off the sign, or people coming up to check them and being able to lift them by the corners or edges.
-Sharon Toji, The ADA Sign Lady