Swirl Snap Bar, Wax Melt Clamshell Packaging Each clamshell holds approx 60 grams of wax. Perfect for creating beautiful packaged wax melts for selling or for gifting. Simply pour the wax into the Clamshell, leave to set and then close... Simple! They are made from recycled PET Plastic and are 100% recyclable. Make sure your wax has cooled and pour slowly. The recommended pouring temperature is 55°C to 60°C but not hotter than 70°C, anything above this could melt the clamshells or create weak spots.