Reflecting the right light
A conventional matte surface scatters both projector light and room light broadly. An ALR surface changes that behavior using layers, ridges or optical structures. In a UST system, those structures are designed around light arriving at a steep angle from very close to the screen.
Why gain can be lower
Many UST ALR screens publish gain figures below 1.0. That does not automatically mean the screen is poor. The optical system is trading some total reflected brightness for better directional control and perceived contrast in ambient light.
Why the material has an orientation
If the microscopic structure is designed to accept light from below, flipping the screen or using a projector from the wrong direction can cause the useful light to be rejected. This is why projector position and screen orientation must be treated as one system.
What ALR cannot fix
ALR cannot fix a dim projector, direct sun pouring onto the image, bad physical alignment or a screen surface that is visibly warped. Think of it as one component of the room/projector/screen system, not a replacement for good setup.
Frequently asked questions
What does ALR stand for?
Ambient Light Rejecting.
What does screen gain mean?
It is a relative measure of how much light the screen returns in a given direction compared with a reference surface.
Why are UST ALR screens directional?
They are engineered around the steep angle at which a UST projector sends light to the screen.
Research note
Product-specific facts on this page were checked against the NothingProjector product listing and related manufacturer listings on September 16, 2026. Where we discuss fit, trade-offs or room design, that is editorial analysis rather than a claim of hands-on testing. Live merchant details can change.