I used them with the standard pink/blue water soluble pencils and because it didn't show up on some of the fabrics I had to go over it several times to darken it enough to see. I had to wash the quilt three times and still didn't get it all out. Since then I've found the washable markers by Crayola and erasable colored pencils by Crayola. I haven't tried the washable for marking stencils but they have worked for piecing.