45,000 martindale. Wool is a natural fiber suitable for all climates. the wool fibres adapt easily to room temperature, having a cooling effect in warm rooms and a warming effect in cold rooms. The fibres are elastic so they tolerate compression and stretching better than any other materials. Wool naturally repels dirt & it is not prone to static electricity. Intrinsically flame retardant, wool has a very high ignition temperature and chars rather than drips or melts.