A length of soft nylon screen works great, but watch out for the edges---they
can catch on the textiles you are cleaning. Masking tape around all edges
helps, but sewing 2" wide archival twill tape around each side works even
better---it'll last a long time.
Also, store the screen flat. I kept one folded for a while, and it became
brittle and cracked in places.
Good Luck,
Ellen