Not sure if you are talking about machine or hand quilting - or if it even makes a difference. I am a hand quilter. Like others, have tried lots of different marking tools that are taking up space in my sewing room. I now use a #2 mechanical pencil on light fabrics and a Bohin mechanical pencil w/white lead for dark fabrics. Both work well for me and I've not had issues with either washing out. I mark as I go and do so as lightly as possible to be able to see the lines. I've also used chalk mechanical pencils (available in JoAnn's and probably other places) and don't mind them either. The regular lead pencils I find are easier to work with and leave a finer line.