I recently got out a piece that I started about 10 yrs ago. It had crayola washable markers on it. I finished it last week but when I rinsed it out there were still a few marks left on it. The brown was the one that didn't wash out completely. But it sat there for 10 years and could have been heat set. Some of the squares were ironed. I was impressed that that much came out. It's civil war colors so you really can't see it much.