I did a Hummell embroidered quilt and I used Mettler Metrosene. It's 100% polyester. The Hummell figurines are not shiny, so it called for a thread that was not shiny. I have even used 12 weight heavy thread for embroidering red work designs. I've used yarn in the bobbin for bobbin work (I have a special bobbin holder. Use what you want.