Have you tried sticky stabilizer--in the hoop and then press the area you want to embroider onto it. Works really good, tho with the weight of the bag moving around, I would put a few pins around the outside edges where they won't be in way of needle. I do many projects where I only hoop the stabilizer and pin my article to it. I rarely hoop my project anymore--I use this method and sometimes use machine basting frames to hold in place.