New York Consolidated Laws, Uniform Commercial Code - UCC § 3-403. Signature by Authorized Representative

(a) is personally obligated if the instrument neither names the person represented nor shows that the representative signed in a representative capacity;

(b) except as otherwise established between the immediate parties, is personally obligated if the instrument names the person represented but does not show that the representative signed in a representative capacity, or if the instrument does not name the person represented but does show that the representative signed in a representative capacity.