The material we use is swimsuit material made from 80% Nylon and 20% Spandex and has a 4-way stretch providing comfort and a perfect fit. The material is forgiving and will stretch when wet. We have thoroughly tested our fabric and know it to be resistant to fading, shrinkage and wear. It sparkles in the light which creates an even greater magical feel. Please remember, like any other clothing item, it can be damaged when rubbing on a rough surface and walking on the tail. It is important to rinse your tail in cold water after swimming then lay flat to dry out of direct sunlight.