There are many reasons why you may choose to make flowers using royal icing. ***Royal Icing is the best icing to use when decorating a cake using flowers cascaded on the sides because it is lightweight. ***Royal Icing flowers may be made several weeks ahead. ***Make dozens of tiny fill-in flowers and have them on hand whenever needed. ***Royal Icing flowers made last minute may be handled by drying in the oven for about 1/2 hour, set at lowest temperature possible. ***Royal Icing flowers will not grease soak.