US SUPREME COURT DECISIONS

l. Where a party to a negotiable instrument entrusts it to another for use as such with blanks not filled, it carries on its face an implied authority to complete it by filling them, but not to vary or alter its material terms by erasing what is written or printed as a part thereof, nor to pervert its scope or meaning by filling the blanks with stipulations repugnant to what was plainly and clearly expressed in the instrument.

2. It is a principle of universal application that the material alteration of a written instrument renders it void.