I have a variety of marking tools and use different ones on individual projects. It is Very Important that you Test your choice to make sure it will come out Every Time, Each new project. Some come out easily one time then don't on the next project. Always read the packaging for removal instructions. You don't want to heat set, cause a marker to become permanent because you ironed over it, or added water when a brush or eraser was all that was needed. I use chalk often. I do like the air/water removable markers but they disappear on their own within a few hours so those I use when marking small areas, quilting then marking next area. I've always had good luck with a good sharp pencil, though I've read comments from people who had problems. In 45+ years of sewing a pencil remains my first choice for marking but sometimes doesn't show up or sometimes I want a heavier mark. What ever you choose to try TEST removal FIRST