Use a gelatin mixture to firm up fabrics like silk chiffon and silk charmeuse. Mix a solution of 1 teaspoon of gelatin with 16 ounces of tap water, then leave it to sit for 30 minutes.
Bring another quart of water to a boil before pouring the mixture into the boiled water. Soak the fabric in the entire mixture for an hour before pouring it out, then place the fabric on a towel. Roll up and gently squeeze the towel containing the fabric, then remove it from the towel and lay it flat to air-dry. Simply rinse out the gelatin to return the fabric to its natural state. This simple technique is used in Paris to stiffen silk couture flowers.