Bill,
I am not a lawyer, but please read the caveats I put on it.

I set it out in full because I do not know how you rc guys handle the films that you use. So I dont know if what I have writ is totally foreign or not...
No trouble for me because I am used to working with the B- series airfoils (5-7% camber and 6% thick) and Thomanns foils.