One major enemy to perforated projection screens is dust that settles on the back of each panel. This dust penetrates the small holes leading to an appearance of panel discoloration. As the dust accumulates over time, the areas of the screen with a framework directly behind the panels begin to appear brighter creating the “birdcage” effect. Dust is unable to penetrate these holes leaving bright seam lines where the framework lies, but a darker appearance everywhere else. A simple vacuuming behind the screen can rectify this, and bring the screen back to like new conditions.