I use the washable Crayola markers, but that requires washing afterwards. Since I always wash my quilts its not an issue for me. There was a time that I used this spray chalk with stencils. It was called Magic Marking spray. I bought this at the Quilting Creations website.
http://www.quiltingcreations.com/sto...=spray+marking It worked pretty good, as long as you didn't spray too heavy.. if you sprayed heavy it would cake up on the quilt top. But you could scrape it off and it washed out just fine.