kru, n. Medium (paper, canvas); the substrate upon which a work of art is made.

usage: In addition to being a generic term for writing and illustrating surfaces, this word is often used (like denlu) to capture the idea of a generic substrate. Such usages can be very literal or very figurative: on one hand, a face is a substrate for makeup, a volume of air and/or silence is the substrate for music, and a volume of air filled with music is the substrate for dance—but at the same time, a soul is the substrate for art and dreams, and a body is the substrate for countless phenomena.

elnapu, n. Substrate.