Gareth Sansom’s extraordinarily eccentric paintings are composed of overpainted and underpainted images—palimpsests of body parts, numerals, words, cartoonish faces, collaged photographs, and feces-like smears. As they sprawl toward their edges, these agglomerations are beaten back by borders of precisely painted, brightly colored abstractions that look at first sight as if they’ve been carelessly assembled from a late-1960s mail-order catalogue of modernism’s formalist tricks. That’s exactly when Sansom started making paintings like this, which have earned him his position as one of