I marked a quilt with the Fons and Porter black watersoluable pencil. On one block I decided I wanted a different pattern. I tried washing those marks out with just a squirt of handsoap. They didn't come out. When I washed the whole quilt after quilting it, all the marks came out except those that I'd tried to get out with handsoap. Luckily, I checked it before I put the quilt in the dryer. I used a little detergent and oxygen bleach and scrubbed them until they did come out.