is the quilt all quilted & bound? have you laundered it? I have used that chalk many, many times over the years- the marks have always come out in the wash- I always launder my finished quilts- in the washer- with regular detergent on a regular setting- the chalk has always been gone when the quilt came out- you didn't say what color you used- once I used the pink and had to spritz with 'shout' in a couple spots to get it all out- I always remove the washed quilt & look it over before drying it to make sure all marks have come out- so I can treat any remaining- that's the only time I had a problem with chalk- since then I just stay away from the pink.