I use the Ultra Clean markers for most fabrics & a white dressmaker's pencil for very dark fabrics. Every so often, I find I need to spend a little extra time hand agitating the fabric, but I've done pretty much anything one could do to a quilt with them on & they've always come out for me. I only work with cotton or wool, though, so I don't know how they'd do with synthetic or semi-synthetic fibers.