I've used these markers as well with good results. One thing I would warn about though is to keep the quilt away from heat until after it is washed. I has a student use these to mark her quilt and after working on it for a while, got bored and put it away for about five months. When she started working on it again, the yellow had started to fade, making it difficult to see. Someone had told her to iron the area and the lines would "magically" reappear. Well, they did reappear and then she couldn't get rid of them - even after a couple of washings.