Plating: Black Metal or White Metal
Enamel: Soft Enamel
Backings: 2 Rubber Backings
Standard backings are either Rubber or Metal Butterfly backings. These will securely hold your pin on, but locking backings are almost guaranteed to keep your pin in place. Think of them as 'pinsurance' for your most prized pins.
Great buying experience and the pins are adorable