This is a 4 way stretch Tricot Lycra that s highly durable and machine washable. It is lightweight and breathable. It can be worn in water, and has been color fasted to reduce and color bleeding (we recommend washing the garment after confirming it is the correct size for your dog). It is similar to the material used to make sportswear worn by many athletes such as runners, bicyclists and gymnasts. We would be happy to send a sample of the material used.