
Thinsulate is a spun polyester fabric manufactured by 3M. It adds warmth to a coat without adding a lot of bulk. I used Thinsulate recently to add an interlining when sewing the Clare Coat for my daughter. She wanted a warm winter coat to handle the blowing winds of New York City, and an interlining, particularly one made out of thinsulate, is a great way to provide that added warmth.