1/2 Inch 18 Gauge Circle Tag with Ring Alkeme™ Metal Stamping Blank. Try Alkeme™ stamping blanks, the new alternative to silver. Developed by ImpressArt specially for metal stamping, Alkeme is easy to stamp, non-corrosive, and costs a fraction of the price of silver. Alkeme is lead, nickel, and cadmium free. Some discs may have light scratches and blemishes that can be polished. 18 Gauge.