1. Measure usable wall width
Do not measure the entire wall and assume it is all available. Subtract space needed for speakers, doors, curtains, trim, cabinets and installation clearance. Then compare the complete outer frame dimensions, not just image width.
2. Check seating comfort
A larger image increases visual immersion but also increases eye movement. The right viewing angle is subjective, so mark the proposed image corners on the wall with painter’s tape before buying.
3. Verify throw geometry
Use your projector’s manufacturer calculator or manual. Zoom range, lens shift, throw ratio and UST cabinet height can all limit the diagonals you can actually produce.
4. Preserve brightness
Increasing diagonal from 100″ to 120″ increases image area by roughly 44%. The same projector output is spread over that larger area, so perceived brightness can fall.
5. Then choose the screen
If your final choice is 100″ or 120″ and you want a 16:9 matte-white fixed frame, the NothingProjector model covers both sizes.
