Language, and its formal and material qualities, are central subjects in Lewis' work. Examining semiotics and drawing as parallel forms of abstraction, he appropriates and adapts forms including the Roman alphabet and the phonetic symbols used in stenography. In his vibrant Shorthand series, Lewis invents and utilizes a signature glyph alphabet based on bisecting lines and biomorphic planes of color encoded with references to specific historical or current events that engage with themes of race, power, and communication. Lewis' work suggests that, as with any social system, language both reflects and actively impacts the Black American experience.
Working with materials such as powdered graphite, pencil, torn paper, and a range of handmade and found surfaces, Lewis' practice is deliberately one of intense exertion. Whether the steadfast application of unruly materials, hours of repetitive shading, or the hand-installation of large-scale commissions, the artist's mark-making is an embodiment of labor. Lewis' physical manipulation of visual systems of language - his erasure, distortion, destruction, as well as the emphatic insertion of his own biography and experiences - turns source material into poetic fragment, bringing forth the subtler ways in which meaning is established and transformed over time.
Across multiple, interrelated bodies of work, Lewis draws from American cultural history and plays with collaborative authorship by using the words of writers, philosophers, and poets as generative points of departure. For an expansive 2018 solo exhibition at Smithsonian's Hirshhorn Museum and Sculpture Garden titled Anthology 2014-2016, Lewis reproduced hundreds of iterations of Bill Watterson's comic strip Calvin and Hobbes, shaping them into visual poems through a process of careful erasure. The televised 1965 debate between James Baldwin and conservative commentator William F. Buckley has also provided a jumping off point for work in multiple media. In a 2025 commission for the Menil Drawing Institute's exhibition What drawing can be: four responses, Lewis constructed a monumental stenographer's mark from rubber bands coated in graphite powder, wound taut around a constellation of screws affixed to the wall. The mark directly referenced the contents of the debate, "Has the American dream been achieved at the expense of the American negro?" which was won by Baldwin and continues to influence discourse today.