I got one of these. IMHO, a waste of my money. used on a wall hanging made in a class. Class was 12 sessions in the middle of winter, average night time tempt about 35 to 40 Every time I took my project out of the house to class, all lines and marks showed up again. Would not have been to bad if it had not been an embellishment class. Some lines still show because I could not get under some of the beads, an ribbon work. I played with the pen, at 42* lines showed up. Tried washing marked fabric, 100% cotton, and blends, with everything I could think of, including bleach. Lines kept returning, and some develop light lines that never went away. Went back to the way I was taught, a sliver of hand soap washes out every time. Gave the pen to DGD to draw pictures with.