Misprinted Bill with a White Section from Missing Printing
The note below is an example of a very minor obstruction misprint. Even in perfect condition, an error that minor won't be worth much more than about $100. The same error on something like a two dollar bill or something with a red or blue seal would carry a premium. Any misprint on a star note will also command an additional premium.
This misprint occurs when something like a piece of paper or foreign object physically obstructs part of a printing. It happens frequently. If your misprint happened to retain the item that caused the obstruction, then keep that item! Retained obstructions are worth much more money.