Halloween Fun Is A-Brewin’ This 6″ Black Cauldron is perfect for conjuring up some great Halloween party decoration ideas! Made of sturdy molded plastic material, these cauldrons have a black matte finish and give a cute seasonal touch to any snack table, store counter, or front porch. A Cauldron To Complement Your Holiday Decor These Black Cauldrons measure 6″ in diameter. They’re right on theme for Halloween, but they’re great for Thanksgiving and St. Patrick’s Day displays too!