Since the official paper no longer functions you have to use aftermarket paper for the Game Boy Printer now. I've found that many of these rolls are larger and therefore don't fit properly within the casing. This is an extended spool holder for use with thicker rolls.

It prints in 3 pieces and then snaps together. To set it up just snap one side to the middle, load the paper, then snap the other side on.

Only the middle part requires supports. Printing it at an angle can help strengthen the tabs but this is optional.