Blanc Seign Law and Legal Definition

Blanc seign is a French term. As used in Civil law, the term refers to a signed paper entrusted to some person with the power to bind the signer within limits of the agreement between the signer and the grantee.

Blanc seign is a paper signed at the bottom by him who intends to bind himself, give acquittance, or compromise at the, discretion of the person whom he entrusts with such blanc seign, giving him power to fill it with what he may think proper, according to agreement." [Musson v. Bank U. S., 6 Mart. (o.s.) 707, 718 (La. 1819)].