I just took a class with Pat Speth (Nickel Quilt lady). She gave the following directions for a design wall. Use the cardboard cutting mat for sewers that folds up. Using extendable curtain rods that have the bent ends, fasten a flannel backed tablecloth (with flannel side out) to the cardboard mat with 2" binder clips over the flannel and curtain rod. The rods are used at the top and bottom to hold the mat open. The size of the design wall can be full size or smaller if you are working on a wall hanging.