Throughout his career, Morandi concentrated almost exclusively on still lifes and landscapes, except for a few self-portraits. With great sensitivity to tone, color, and compositional balance, he would depict the same familiar bottles and vases again and again in paintings notable for their simplicity of execution. A prolific painter, he completed some 1350 oil paintings. He also executed 133 etchings, a significant body of work in its own right, and his drawings and watercolors often approach abstraction in their economy of means. He explained: "What interests me most is expressing what’s in nature, in the visible world, that is".