as-warm-as-choco:

Before the computing era, ILM was the master of oil matte painting, making audiences believe that some of the sets in the original Star Wars and Indiana Jones trilogy were real when they weren’t. They were the work of geniuses like Chris Evans, Michael Pangrazio, Frank Ordaz, Harrison Ellenshaw and Ralph McQuarrie ! Forever thank you, to their handmade art and the work of their colleagues, that made us dream of impossible worlds and fantastic places across Earth and the Universe.

There are more background paintings on this article, featuring comments by the masters/artists themselves ! 

Some of the following pieces were made by other artists 2: