I have only marked a quilt once with a regular graphite (#2 lead) pencil. I starched the top heavily before marking because I had read that the lead will be on the starch and not get imbedded in the fabric. It worked out fine. The marks washed right out when I was done. The quilt was hand quilted and it took me several years to complete it (got put to the side untouched for a good 9 months). The marks remained visible that whole time. I used a stencil for the markings. It was a Lone Star quilt so I only marked the stencil in the corner squares and setting triangles. The rest was simply background cross hatching that I used painters tape as a guide and the star itself I also used tape to outline quilt 1/2" from every seam. So it was minimally marked.