wall fabric ideas

We are in the process of bidding on the home of our dreams and I am planning how to light-proof and sound-proof our bedroom since my husband needs to have all light blocked out in order to be able to sleep (and he works odd hours)...
I came up with the idea of somehow putting up fabric on the walls, but I don't want a bunch of staple holes in the wall when I am ready to change it or it's time to move someday (perish the thought)...

I want to apply the fabric not straight up and down but in swirls, softly... not only will this make the room more sound and weather proof, it will make a unique look to the room. However, I don't know what I can use to be on the back of the fabric. Is there some sort of foam core board I can use and just tack up on the walls with a lathe strip or something? Then I could staple or pin or glue or whatever I want without worrying about it..? Or maybe foam or cork board (which is sounding really interesting) on thin plywood nailed to the lathe board and then crown molding over the top and bottom of the lathe?

Help me figure out how to do it! Where would I get the stuff I want/need to work with, too? I need your ideas!

Thanks,

Love in Christ,
JanieJoy