I believe there were some issues previously with the methods used for implementing the BIP38 encryption, which meant that sometimes you could run into difficulty when trying to decrypt them. There was one particularly nasty episode of this when it required a specific browser version on a specific operating system!
If you're worried about it, what I would suggest doing is create a throwaway wallet using the original method, and then attempt to decrypt it using various methods (bitaddress.org, blockchain.info etc)... that should at least prove that the systems you are using are compatible.
OK Ill do that thank you
There were some issues.
You should be downloading the javascript and running it locally, not typing these private keys into any online website. And the local computer should be off the internet when this is done.
That's not really great, better is a linux OS on a flash drive so the computer stores and knows nothing.
Anyway, here is what you should do. After moving the coins, simply print out a copy of the code (that's the downloaded and locally ran copy of the, whichever, for example bitaddress.org) that you are using to do the bip38 encryption.
Store that program code with the paper wallet. Include notes as to your OS version and whatever else you think might help someone off in the future.
IF you did this with a copy of bootable linux on a flash drive, and the files mentioned above were on the flash drive, then you could store this flash drive with the paper wallets. You are then saving with the wallets, a known good computing environment for their deciphering.
