100% Polyester. Gentle Cycle Wash and Hang Dry or Dry Clean (Recommended) as it will lengthen the use of your dress. A garment Steamer will help eliminate wrinkles, and create a voluminous and full dress! * A Size 6 is for the Average 5 to 6 year old girl. A Size 8 is for the average 7 to 8 year old, etc. Using the Size Chart as a reference, a size up or down from there (if necessary) will get you to the right fit!