/ic/ - Artwork/Critique

I'm growing crystals as a hobby and I am planning to grow them on plastic, plexiglas or maybe even wood to hang it up like a painting.
Here's my problem: I need to make sure they don't fall off. would hairspray do the trick?
again, I am growing them on the surface, not glueing them on.
I'd just need some kind of thin layer as protection.
any ideas?