I am a hand quilter too, I mark as I go. I am working on a piece for myself that I marked with a pencil and I didn't like the pattern I have washed it several times and I still see the pencil mark. I used the grayish pencil, I can't think of the name but the leading quilters pencil. I have to say I like the disappearing or wash away markers I have had great luck with those. Although, I never use those on old vintage fabrics when restoring quilts. The only thing about the chalk that I have found is that it is dusty and if you have allergies it can trigger sneezing attacks and coughing and it really dries out your fingers and hands. I guess it is just trial and error. If you are leery about the pencils mark a piece of muslin first and then throw it in the washer and see if it comes out. I will definitely be doing that the next pencil I use.