I have used them quite a lot and really like them and have never had a problem washing them out when I wash the quilt. I always wash my quilts in the washer and with HE detergent because I know that is how it will be laundered in the future. I like the fine tip because I can use it with a stencil. However, it is best to mark lightly so you don't ruin the tip. I personally do not care for frixion pens. They do mark well and iron off nicely. However, because they will reappear if put in a cold atmosphere I know there are chemicals left behind and we really do not know about how those chemicals will affect fibers of fabric and/or thread in the future. I am not willing to take the chance. A good example from the past is the use of salt mordants on silk fabrics.