Wool is best known for his paintings of large, black, stenciled letters on white canvases. Wool began to create word paintings in the late 1980s, reportedly after having seen graffiti on a brand new white truck. Using a system of alliteration, with the words often broken up by a grid system, or with the vowels removed (as in ‘TRBL’ or ‘DRNK’), Wool’s word paintings often demand reading aloud to make sense.
At 303 Gallery in 1988, Wool and fellow artist Robert Gober presented a collaborative exhibition and installation which included Wool's seminal text-based painting, Apocalypse Now (1988). The work features words from a famous line in Francis Ford Coppola's film Apocalypse Now, based on the Joseph Conrad novel Heart of Darkness. From the early 1990s through the present, the silkscreen has been a primary tool in Wool’s practice. In his abstract paintings Wool brings together figures and the disfigured, drawing and painting, spontaneous impulses and well thought-out ideas. He draws lines on the canvas with a spray gun and then, directly after, wipes them out again with a rag drenched in solvent to give a new picture in which clear lines have to stand their own against smeared surfaces.
Writing in 2000, in The New York Times, Ken Johnson highlighted Wool's response to an observation made on the street as significant, "in the 1980s, Christopher Wool was doing a Neo-Pop sort of painting using commercial rollers to apply decorative patterns to white panels. One day he saw a new white truck violated by the spray-painted words 'sex' and 'luv.' Mr. Wool made his own painting using those words and went on to make paintings with big, black stenciled letters saying things like 'Run Dog Run' or 'Sell the House, Sell the Car, Sell the Kids.' The paintings captured the scary, euphoric mood of a high-flying period not unlike our own."