We use top-grain, aniline-dyed leather on all visible cushion surfaces. Inside each cushion is high density, HR (High Resilient), Multi-Density polyurethane foam surrounded by Dacron batting. On the LC2 seat cushion, there is a layer of goose down/feathers on the seat top. On the LC3, the seat cushion has an extra layer of Dacron fiberfill. The LC3-relaxed uses both foam and goose down/feathers on the side and seat cushions for the most comfortable of the Cassina style chair: http://bit.ly/19LlgD1