Dune: Part One is another example of the atmospheric sci-fi that director Denis Villeneuve has become famous for, he also directed Arrival and Blade Runner 2049, and you can have the same flavor in Dune. The new movie in particular sports some immense alien worlds that tease distant horizons, even in internal spaces. You’d be excused for thinking that some of these interior sets, like the fortress of Arakeen, were constructed with green screen sets, but this is not correct.
As SlashFilm details, production designer Patrice Vermette avoided the green screen by using simply painted fabric.
Vermette, who is going to work on Dune: Part Two and Tron 3, said that the production crew created an interior set higher than 24 or 30 feet all out of fabric. This fabric was replaced in post-production by the usual special effects software, but the true benefit of fabric was giving actors and artists a more believable space to work in, rather than a boring and dull green screen.
Painted fabric to mimic what the set would eventually look like also allowed post-production artists to bypass having to paint out awkward green shades of color created by green screens. The use of fabric to reflect a deeper space than is financially or physically possible is a standard practice in theater, where characters are usually limited to a small stage.