id try several sizes.. and see which works the best. maybe a #2 in the 1/8 oz, and #1 in the quarter oz. you can call do-it and see what they reccomend for the molds. a reccomendation might be in your instruction book that comes with the mold. I dont mold nothing larger than 1/16th oz and i use #4 gold. and #6 in 1/32 oz.