Superior Printing Ink, Co., Inc. has hired two key employees to serve in its sales and technical areas.      The company has appointed Daniel C. Maffeo as vice president, sales. Mr. Maffeo’s responsibilities include managing Superior’s national field sales organization and manufacturer representatives. He works closely with Superior’s regional, district and branch operations managers. His responsibilities also include overseeing marketing and communications. He reports to James La Rocca, senio...