Why can't you use tiger tape (1/4 width) or blue painters tape to mark the top of the quilt? You might not beable to tape the entire quilt at one time but add a few rows at a time. Just a thought. I know my Mom made a quilt for a quilt show and sent it to the LA she had marked the quilt for quilting and the pen which was blue did not come out so she wasn't able to put it in the quilt show. She was very disappointed alot of work went into the quilt.