Are you refering to the Stained markers? (Not Stained Glass) I used a blue one not long ago to touch up some fabric that had faded unevenly after being washed. It worked really well, the color was soft rather than sharp or crisp but I only used the one color. The quilt hasn't been washed since the marker was used on it as it is a wall hanging, so I don't know if it is colorfast.