High quality stove enamel. The holes matched perfectly. No sharp burrs or anything to snag stored items. Stays flat under load. Even I've been on 200 lb pigs standing on 2 steps. Cons: Anchor bolts are too large in diameter and too short for anchoring 2x4 drywall. Used #6 x 3" pan head wood screws. Also the hardware is doubled, only 6 nuts, bolts and washer sets are needed, not 12. Very happy with these supports.