Transacting with Bitcoin and Bitcoin digital wallets is still a challenge for many people who are more familiar with paper currency and physical wallets. What if you could use your home printer to print a paper document that has enough information to unlock a specific amount from your account like $20 USD worth of bitcoin?
When you hand somebody the bill, they still have to use a smartphone app to validate that the bill is valid and remove the $20 worth (or a smaller amount like remove $4.75 and return $16.25 to your main account). However, you don't have to feel like you are carrying around your entire balance but only the subset you want to have accessible for purchases. A lost physical wallet with $60 USD worth of bitcoin is still lost bitcoin just like a real wallet, but that is a smaller amount than having your entire balance at risk if your digital wallet is lost or compromised.
The key insight here is that paper currency offers a built-in limit to an amount to risk. This is an attempt to mimic that characteristic in cryptocurrencies while providing a more physical way of interacting.
Status: There is a cool company called Noteworthy ([https://noteworthy.ag/](https://noteworthy.ag/)) that has created real Bitcoin paper bills in specific denominations that can be "emptied" but don't have to be. A different idea but similar goals and a very good execution.