What is a misprint disc?
Misprints are perfectly manufactured discs with cosmetic flaws in the printing. In Ultimate circles they are also known as practice discs.

A misprint typically has one of two problems: the foil used to stamp the artwork onto the disc is flawed, or we goofed and used the wrong foil color or artwork.
When either occurs, we don't expect the customer to pay for it; instead, it goes onto a shelf with other misprints. When we get too many, they are offered for sale to the public at very low prices.