Magic Lantern slides

[The Village Framer]

Hi all, I'm working on framing a set of four glass slides from a Magic Lantern (an antique type of projector). The paint on the back of the slide is pretty fragile and I'm just curious if anybody has any tips for what sort of backing would "chafe" the paint the least during normal expansion and contraction (of the backing material). Or if this is even a concern...
The photo below is a pic I found online to give a sense of what I'm looking at. All of the black areas and the image is some kind of paint that looks a bit like tempera.
Has anybody worked with these before?
http://thumbs3.ebaystatic.com/d/l225/m/mHyss8GKpBdNErOH8qUdanQ.jpg

 

[jim_p]

I would treat this like an animation cel and raise it up so it's not touching the backer board at all...