Kazuo Oga is one of the most inconspicuously famous artists, which is inspirational in its own right by how humbling it is. You would think they were digital from an immediate approach, however upon closer inspection of the textures, lighting and layering it’s clear they’re perfectly hand crafter watercolour pieces.
His works, featured in the backgrounds of various Studio Ghibli films, are subtle enough to blend into the background of the films yet stand out alone as perfection of watercolour techniques and command of lighting.
Just considering there are scenes where the camera pans across his works for several long moments reflects the sublime quality of his work. And that he was able to develop enough artworks to supply several films with stunning backdrops is nothing short of breathtaking.
That’s a good word for it, “breathtaking”.
I’m like 90% sure they were gouache or poster-paint though; it’s pretty hard to get a thick and solid/opaque effect with watercolour. Also because using gouache/poster-paint is pretty old-school industry standard.
edit: oop, I researched and found out that apparently every single ghibli bg were all made with poster paint (*do a little i-was-right dance*). You can find out more here (someone in the comments even has a name for the products ghibli uses, so maybe you’ll be able to purchase it online somewhere.)