I am using RobKhor's printcoins project. It is online at http://print.printcoins.com. I don't use the online version. I downloaded the project to my off-line bitcoin machine (Raspberry PI) and I generate the bills on that. It's completely offline. It takes a while to generate on such a low powered machine but I don't have to worry about it being comprised.

I generate vanity addresses for my coins. "1BTC....", "1Coin....", "1Half....", 1ooBTC....", etc.

I added BitPay's Leonardo note to Rob's project and it is now part of the main project on github.  I also added a turning note from another project I found made by aristus.

I have since talked to Anthony (?) at BitPay and he sent me the layered images for his notes so the one I'm using now is slightly different than the one in the printcoins project. I intend on adding it to the project soon though because I think it's prettier.

Additionally I will be adding the bitpay "bond" but I have not come up with a design modification I'm happy with yet.