https://youtu.be/lQTdOcYK9Ds
Documentary about how traditional glass matte paintings were created and used at ILM and many other studios.
In the days before green screen, CGI and “virtual backlots,” you fused carefully matted-out live footage from the set, with backdrops hand-painted to match the footage’s lighting with corresponding transparent parts, double-exposing that footage through the glass, using rear projection.









