How to transfer BTC between paper wallet and an exchange? I am new to the paper wallet, and have a few questions about how to use it. Concretely， I am following the instructions here (https://walletgenerator.net/) to generate a paper wallet for BTC, but I am wondering 1. How can I transfer BTC back and forth between my paper wallet and the GDAX exchange, and 2. Is there any fee to do such transfer? Thanks!
Paper wallets are often a very secure way of storing bitcoins for the long-term but not for two-way transactions.

You can easily transfer bitcoins into your paper wallet from GDAX by going to WITHDRAW FUNDS and putting in the public address part of the paper wallet.

Sending bitcoins to GDAX from a paper wallet is more complicated.
You will need to import your private key into a real client.

Once you imported the private key into your client wallet it will allow you to spend your bitcoin and send it to the address provided on GDAX.

Current fees for bitcoin transaction can be found on miningfees.com