if it is a sweatshirt type fabric that the needle goes through, I'd try using a ball point needle, or put a wss stablizer on top and bottom. I always use a stablizer in the hoop when I'm using the embroidery module. It takes the stretch out of fabric. She when you have a big piece of material, there is more stretch than on a smaller piece since it is moving all that fabric around and it pulls on the whole thing. I'd try using a wss on the top and bottom and see if that works. It'll wash out, so the fabric will maintain it's nice feel.