The prevalence of colourful metaphors and figurative language in critics’ descriptions of artworks has long attracted attention. Talk of ‘liquid melodies’, ‘purple prose’, ‘soaring arches’, and the use of still more elaborate figurative descriptions, is not uncommon. My aim in this paper is to explain why metaphor is so prevalent in critical description. Many have taken the prevalence of art-critical metaphors to reveal something important about aesthetic experience and aesthetic properties. My focus is different. I attempt to determine what metaphor enables critics to achieve and why it is so well suited to helping them achieve it. I begin by outlining my account of what metaphors communicate and defend it against objections to the effect that it does not apply to art-critical metaphors. I then distinguish between two kinds of art-critical metaphor. This distinction is not normally drawn, but drawing it is essential to understanding why critics use metaphor. I then explain why each kind of metaphor is so common in criticism.