Using stencils (unless the kind with mesh openings which require a pounce to work right) I use either a foam paint brush with plain white chalk, or a blue water soluble marking pens. If I just want a quick mark for a immediate quilting, I'll use a purple air erasable marker. I also use a Bohnin chalk cartridge (avoid yellow) and sometimes the F & P ceramic chalk marker for fine lines. I've used the Crayola Ultra Clean Markers twice--the first time no issues, but the second time was a disaster. It was a friend's baby quilt and the center motif would not wash out. Took 3 washings. Gave the markers to the grandsons!