Take in minds that it’s very import to store the master key into a safe place / device. It’s easy to stole your token and at the same time it’s easy to watch you when you are writing the pin code.
If you lost the token (sub keys), with the master key you can revoke the sub keys and create a new set, keeping your identity safe. If your master key is stolen, you will lost, in some way, your identity and your network of trusts. In this case you need to generate a new master, sub keys, and rebuild your friends network from the begin (after you send revoke certificate for the master key to key servers).
For this reason I prefer to keep the master key on a cold storage and on a separate smart card (stored in my home) that I will use to sign pub keys only, and only subkeys into the token for everyday use.
Keep you safe, keep your master on the paper 
ciao
luigi