Wool outperforms polyester, down and foam across every metric that determines sleep quality. Independent testing by SATRA (UK) and NZWTA (New Zealand) confirms Wisewool™ wool batting retains approximately 95% of its thickness after 80,000 pounding cycles, while polyester lost over half its hardness in the same test. A 2026 Bangor University study found wool duvets transmitted 139% more moisture than synthetic alternatives at elevated temperatures, where condensation actually formed inside the polyester duvet.