Although scholars have paid increasing attention to textual marginalia and their role in the consumption and production of texts, they have largely overlooked the phenomenon of doodling and its parallel role in reading and writing. Doodles trouble their accompanying texts; they record inattention, whimsical digression, critique, and sometimes outright hostility toward those texts, revealing the complexity of readerly response and exposing authors’ visions as less unified than they seem. By attending to doodles in manuscripts, notebooks, and published literature, scholars can gain insight into the subconscious and occasionally contradictory forces at play in textual genesis and reception. This article examines doodles and closely related drawings by three author-artists from the long nineteenth century: Max Beerbohm, G. K. Chesterton, and an amateur illustrator named E. Cotton. Their work demonstrates the importance of doodling to their respective authorial enterprises and reveals the (sometimes ambiguous) generic boundaries between doodles and related graphic forms.