Mounting a TV behind glass is not very difficult to do and as long as you maintain some simple guidelines, which Ramsin Khachi has provided, the results will be stunning.
Ramsin’s Tips:
A. Never use a plasma TV or one that generates excessive heat.
B. Always ensure there is adequate ventilation for the TV
C. There are three materials you can use, one way mirror, regular mirror and back painted glass
D. For one way mirror, apply some opaque or solid vinyl or film onto the back of the mirror. This is to mask the mounting elements from being visible. Prior to applying film, position the film and TV and mark the area of the screen onto the film and cut out using a utility knife. Using a light soap solution will allow for easy installation of the film. Squeegee all bubbles and let dry. Once set, take two strips of 3/4" or 5/8" plywood equal to width of TV. Measure distance from bottom of screen to bottom of TV frame and transfer that measurement to from the bottom of cutout down. Glue one strip of plywood using clear silicone at the mark. Once set, it will align the TV to the opening and hold it from sliding down. Glue second piece to accommodate full height of TV. Apply foam weather stripping around face of TV frame. Once silicone has set for 24 Hrs., place TV between strips of wood and align so that screen is lined up to cutout from side to side. Using plumbing all-round straps or similar, trap TV from wood strip to strip. Fasten using screws shorter than thickness of plywood.
E. For regular mirror, the silvering will have to be removed to accommodate screen size. This will have to be professionally done through mirror shop. Apply TV as above.
F. For back painted glass, order glass back painted with a clear area for the screen. Apply TV as above.
G. Infrared functions may work depending on TV style. If the functions do not work through the paint or mirror, use an infrared repeater kit available through high end stereo shops.