I use a regular #2 mechanical pencil for marking on light fabrics and the equivalent Bohin mechanical pencil with white chalk/lead for marking on dark fabrics. I've tried any number of methods over the years and these are the only ones I now use. Only had an issue once with the regular lead pencil but I think I was probably a bit heavy-handed that time as well as changing my mind on the quilting design so it was pretty obvious. But 'scrubbing' with some liquid dish soap and a soft toothbrush, it eventually came out as well. I, too, mark as I go now as most times the marks will wear off after time. And we all know how long it normally takes to get something hand quilted!