Navy blue corked sewn to luxury black cotton. All our slippers are made from Portuguese imported cork, are vegetable dyed, lined with premium earth-friendly fleece with a soft eco-lux fabric backing to ensure no blisters or rubbing occur during wear. Our elastic has been tightened to perfected and our slippers fit best without socks, our slipper is designed to regulate heat during climate conditions (keep cold in summer and hot during winter) therefore barefoot is preferred.