Polyester,SatinIron On Low Heat,Use Neutral Detergent,Dry Cleaning,Hand Wash,Do Not OnlyHigh quality silk like satin pajama pants for men, 100% polyester bottoms.Elastic waistband pants with drawstring, two side pockets.Silky feeling smooth touch mens lounge pants perfect home wear design. Good choice for Father's Day gift.New dark colored fabric will lose floating color from its surface, especially black. We suggest you wash your new satin products before wearing. If possible, please use neutral detergent to wash, soap or alkaline detergent may increase fading. Wash separately or with like color, wash inside out can help protect fabric color. Hand wash below 30 Celsius Degree. Iron on low heat.For size guide, please scroll down to Product Description.