Did you heat them at all? That could make them permanent. I've used this pencil as well (the pink) and did have to wash the finished quilt several times to remove all remmnants of the markings. I only used cold water the first time, then washed a couple of times with detergent & oxy-clean. I think it was a total of 3 washings before all the marks came clean. Be sure all marks are gone before drying in the dryer. For me the blue pens that are removed by water seem to work the best, but sometimes even those have to be washed more than once.