I've used sharpies and they work wonderfully. They don't rub or wash out! I bought a set that are fine tip and told the kids "Hands Off" - these stay with my quilt stuff and don't get used for anything else!! My daughter was going into withdrawals practically because she couldn't use them. I had to grab a Michael's 50% off coupon to go get her a set for own use. Now, they sit quietly in my quilting drawer..no kids allowed!!