Zinc Alloy Enjection molded items can be simple lapel pins to sophisticated multi function pins, medallions, keychains etc. Hot liquid molten alloy is injected into a mold. Injection molding is recommended for products larger than 2″ in length, and for lapel pins or keychains that have numerous cutouts. Zinc alloy injection is a great substitute material to brass. The recessed areas are hand-filled with brilliant enamel colors and can be PMS color matched.