Cut a rectangle from gray flannel fabric using scissors to measure 3 feet wide and 6 feet long.
Cut a rectangle from gray tulle fabric using scissors to measure 3 feet wide and 6 feet long.
Place the two rectangles together, lining up the edges. Sew along one of the short edges to secure the two fabric sheets together.
Place an expandable curtain rod horizontally onto a table. Fold the sewn edge of the fabric over the curtain rid with the flannel side facing up.
Pin the folded edge onto itself using straight pins to secure the fabric around the curtain rod.
Sew the pinned edge using a needle and thread. Remove the straight pins.
Cut out an inverted triangle from the gray flannel fabric using scissors, cutting the sides of the cutout to look jagged and ripped. Discard the cut-out section.
Cut a vertical slit straight up the center of the tulle fabric.
Spread white cobweb material across the front of the gray flannel, and stitch the cobwebbing in place. You can now hang up the curtain rod into a doorway to create a novelty door curtain for Halloween.