To stop the band from rolling up under the bust, use 5/8-inch strap elastic (which has a plush side and no decorative edge) instead of standard picot elastic. 2. Tailoring & Pattern Adjustments
For costume enthusiasts, standard foam patterns often don't provide the necessary curvature for a larger bust.
Rather than using a single 6mm piece of foam, layer three 2mm EVA foam sheets together with contact cement. This "sandwich" holds a curved shape much better under the weight of a larger design.