When at a LQS the owner demonstrated the miracle chalk. This product will mark stencils. The chalk will stay on if you hand goes over it and when folded up. To remove you simply iron it out. I have used it twice on dark fabric and it is great. You cannot see it good on light fabric but the company suggested using a black light. Have now tried that yet but I am sure it will work. You can order it on line on their website of miraclechalk.com. Great Stuff.