Ad Reinhardt's Black Paintings are the most radical reductionist statement in post-war American art — 5×5-foot square canvases painted between 1953 and 1967, each a nominally black surface revealing on close inspection a barely-discernible cruciform of red-blacks, blue-blacks, and green-blacks in a 3×3 grid. This design system channels that dogmatic austerity: no decoration, no atmosphere, no expression — only the proposition of absence rendered in near-black variations.