Water soluble marking pens. They glide across the fabric without bunching, but you can't iron over them or spray them off with a plant mister. Submerge your quilt when finished and the marks will come out completely. Do this before laundering as some detergents can set the marks BROWN if they are not removed with plain water before washing. As with any marking instrument, TEST MARKER ON YOUR FABRIC FIRST BEFORE USING IT IN A PROJECT. Blue "Spit Pen"This water erasable marking pen has a pin point nib for extremely thin lines. Read package directions for use and removal. $2.75 Pink "Spit Pen"The wider nib on this pen makes for a "juicier" line. It glides over the fabric very easily. Read package directions for use and removal. $3.99