I am building some mando armor of my own design for a fan film. Because it's for a fan film, it needs to be sturdy enough for the actor to run around and do choreography in it without it flopping around too much. The problem is, though, it plops around.... a lot. How can I get around this? I assume it might work better if I used a sleeveless shirt to hold the armor on, but I still think it will be too loose. Should I put cardboard behind the armor to keep it steady? what should I do?