We used IFOHA digiline contrast back projection film. Which had teething problems; to begin with, we forgot to peel away the protective film, but once we got that sorted, the film adhered perfectly, no bubbles.
Using tracing paper for the back projection surface.
Ordered the tabletop to be cut out of 18mm MDF from the CNC workshop people
After an insightful conversation with my good friend and furniture designer Andrew Stafford, we agreed that we should first attempt to build a prototype, to test the technology and the design concept. So without the need for design refinement, I set about building the simplest (and cheapest) framework for the surface to sit on.
8mm Endlightened XL plexiglass made by Evonik. Cut from a huge sheet, which left us with enough material to make another one!