1. To find the mirror side of a teleprompter mirror, use the “fingernail test.” Place your finger on the glass. If there is no gap between your finger and its reflection, that is the mirror side.
2. Alternatively, you can look for a double image. The mirror surface offers a nice, crisp reflection with no double image. The non-mirror side has a faint double image, known as “ghosting.”
Illustration of “Ghosting” as seen on the non-mirror side.
Crisp reflection is seen on the mirror side:
For a Mirror TV installation, the orientation of a dielectric mirror won’t have a noticeable affect on the reflection. By convention, mirror side typically faces outward, closer to the observer.