you get them when you get a job there. Talk to the assistant curator
You have no way of going to the Supply Room until you are given the key by the assistant curator. (Complete the Forgery Training.)
Get the paper
In the supply room
the supply room is in the mussem on the first floor to your far left
The keys on Counterfeit Island :The Supply Room - pass the forgery test trainingThe Inspector cottage - from the lady curator (late in the game)The dragon face lock - collect the six picture piecesThe Black Widow's door - you get the key card in the chase
finish the tests and he will give u a key.
Don't ask me, o_o.
there is a job aplication so go for it get the job and you will get supply room keys
The keys on Counterfeit Island :The Supply Room - pass the forgery test trainingThe Inspector cottage - from the lady curator (late in the game)The dragon face lock - collect the six picture piecesThe Black Widow's door - you get the key card in the chase
Apply for the job with the assistant curator and when you pass the Forgery Detection class, he will give you a key to the Supply Room.
Once you pass the test by the assistant curator, and finish the Forgery training, he will give you a key to the Supply Room.
The same way you got in to get the picture piece : use your key.