The study of early modern diplomatic history has in recent decades expanded beyond a bureaucratic, state-centric focus to consider the processes and personal interactions by which international relations were maintained. Scholars have begun to consider, among other factors, the role of diplomatic gifts, diplomatic hospitality, and diplomatic culture. This article contributes to this discussion from an East Asian perspective by considering the role of ‘brush talk’ – written exchanges of classical, literary Chinese – during diplomatic missions from the Korean Chosŏn court to the Tokugawa Shogunate in Japan during the seventeenth through nineteenth centuries. Drawing upon official records, personal diaries, and illustrations, I argue that brush talk was not an official part of diplomatic ceremony and that brushed encounters with Korean officials even extended to people of the townsman classes. Brush talk was as much about ritual display, calligraphic art, and drawing upon a shared storehouse of civilized learning as it was about communicating factual content through language. These visual, performative aspects of brush talk in East Asian diplomacy take it beyond the realm of how a lingua franca is usually conceived, adding to the growing body of scholarship on how this concept applies to non-Western histories.