There is a product called "Do Sew". Use to get it at the Stretch and Sew stores but have to order it online now. It reminds me of an inter facing fabric. You trace the pattern on it and use the traced pattern instead of the original. You can iron it smooth after it has been folded in the pattern envelope. Very durable. I would think less bulky for storage than the muslin. It also sort of sticks to fabric so less pins used.