I can see a couple of problems. First off, you need to make sure that you keep them in safe but physically isolated locations as if something like a fire happens in your house and all your copies are there you are screwed. Next, you might want to have encrypted it with BIP38 just in case someone managed to break into your house or wherever you are storing it and just copied then private key and stole your coins (possibly not needed if you have it in a safe/bank safe deposit box - although you might not trust the banking staff).