I was watching a cooking show. They were baking some sort of delicate pastry and using a teflon liner on their cookie sheet to prevent sticking. I thought "Wow! It takes heat and nothing sticks to it". Brilliant, Huh?
I've been using ever since but, like Les, I've never had a problem with well trimmed prints sticking to either a museum board or kraft paper cover sheet.
The teflon stuff is unbeatable for tacking though and would probably be handy for those who dry mount using a hand iron.