Iron freezer paper to the wrong side of the fabric to stabilize. Get file folders and cut out the *finished* leaf size from the front cover. Tape freezer paper backed square behind file folder cut out (experiment with painters tape and masking tape to see which works best both in terms of stability and for ease of swapping out the old fabric for new). If you set up a table for guests, have a stack ready for people to use. You can swap out fabrics in the used folders and recycle them. Basically the folder cutouts ensure guests will not write into the seam allowance. Freezer paper stabilizes the fabric so it doesn't move as they write. Have extras on hand for mistakes. The fabric is hidden inside the folder along with the tape.