Copy paste the paper into PGP/GPG. Encrypt. Print it and the private key ... use a really complicated pass-phrase you also have to write down to be able to remember or it will be too easy to use the copy of your private key? Store in 3 places .... ehh
But if you're going to use a complicated passphrase anyway, why go through the GPG step? Just use a complicated passphrase (or a whole paragraph) as a brain wallet and store the funds in the related address.
Because brainwallets can be brute-forced just by looking at the blockchain (observe an address with funds + use a huge dictionary to find a passphrase that generates a key which matches the address). This has happened multiple times. If you want to brute force an encrypted paper backup you first have to get access to the paper.
Brainwallets are generally a bad idea because the passphrases that normal people can remember are not strong enough to withstand a brute-force attack. If the passphrase is complex enough you have to write it down, and you might as well have written down the private key in the first place.