I love them. I tested the roller ball and highlighter types. I colored patches of each ink on a strip of white fabric, left them to dry, ironed them away, put them in the freezer and some of the color came back.
I washed them in my hands and all traces were gone. They did not come back in freezing. Since I wash virtually all my quilts before giving them away (to fluff and soften them and remove all the starch I use) I am not even a little bit worried about them.
I have tried to find evidence of the ink remaining in laundered quilts under a magnifying glass and even the areas where I used them to lay out guidelines for quilting, there is not a trace. Most of the marking is in the inseam, but I do use them to mark the spines for feathers, or the circles for the base of feather wreaths, etc. I mostly use the highlighter colors for marking for quilting.
I've heard that some of them leave whitish markings on dark fabrics after ironing and I've seen that, too - but never on a hand-washed or machine laundered quilt.
