Another word for coarse is impasto technique, where the paint is so thick the painting-knife or brush strokes are visible and leave a pronounced texture (e.g. Van Gogh, Rembrandt).

Another cool prompt could be specific painting techniques (e.g. pencil shading, glaze) as if you were training an actual artist in a specific technique.

Just asked sora for an impasto image of a coca cola bottle. But it still came out looking like a coca cola ad/AI art. Super glossy, slick, meaningless. It didn't look like paint. (And the logo wasn't impasto, which I thought was interesting - I guess that logo's utterly ingrained in the model, it's seen it so many times).