Start with projector geometry, then room light, then screen gain and mounting. That order prevents the common mistake of choosing an ALR material by marketing percentage before confirming whether its optical structure matches the projector.

1. Confirm throw type

Standard/long-throw, short-throw and UST projectors send light to the screen from different angles. Directional ALR surfaces are built around those angles.

2. Define the ambient-light problem

Window direction, ceiling fixtures and bright surfaces matter. ALR is most useful when stray light can be reduced but not completely removed.

3. Balance gain, size and projector output

A lower-gain screen can still look better in a lit room if it protects contrast, but the projector must have enough output for the chosen diagonal.