Please test first to ensure these products work for you on a scrap of the muslin you intend to use. You can try using Saral graphite transfer paper and a stylus. I describe how to do it here:
http://www.quiltingboard.com/tutoria...g-t275470.html
While this tutorial uses white transfer paper on a dark fabric, the principal is the same using Saral graphite on light colored muslin fabric. Sometimes the first mark is clear and dark enough that you don't need to go over it again.