For different color of fabric I will use different marking pencils. Usually the white Multi-Pastel Chalk made by General Pencil Co, and light gray and sometime dark gray. They erase and wash out. I am afraid of the Fixon because even tho the color comes out with iron, the chemical is still in the fabric. I know the lines will reappear in cold but it is other qualities that make me fearful of using it. While everyone laughs and says they will never put their quilt in the freezer, I wonder what would happen if the quilt was in a cold climate and in a cold room. Some rooms get as cold as the freezer in the winter. And if we give the quilt to someone else we never know how it is to be used.