All shower caps are lined with a very soft, lightweight pvc fabric, to make them completely waterproof.  They are made to a generous size so that they don’t leave unsightly elastic marks on the forehead, whilst keeping the hair dry. The outer layer fabrics used to complete each hat are all washable, and in fact, we recommend you give your hat a gentle hand wash from time to time, to remove any watermarks and maximise its lifespan.