Cotton Scrim and Cyc Fabric
IFR muslin is available in 128” width only and comes in white, natural, and a variety of colors.
For a variation on the effect, scrims can be painted. When lit from the front the scrim will look like a solid painted drop, but with a shift of the lighting can fade out or completely disappear in an instant.
Keep in mind that the width of the fabric will become the height of the finished scrim, so stages greater than 31’ wide can still get a seamless scrim.