Panel-to-panel transitions are the basic grammar of comics

McCloud categorizes the ways one panel can lead to the next — moment-to-moment, action-to-action, subject-to-subject, scene-to-scene, and more abstract or disjointed jumps — arguing that each transition type asks a different amount of interpretive work from the reader and produces a different pacing effect. Choosing a transition isn't a neutral technical detail; it directly shapes how the story feels to read.

He notes that different comics traditions favor different transition types by convention — some genres lean heavily on action-to-action sequences that keep momentum high, while others use more contemplative subject-to-subject shifts that slow the reader down and invite reflection. Understanding the available palette lets a creator choose deliberately rather than defaulting to habit.

The reader's mind fills in the gap between panels regardless of which transition is used, a process McCloud treats as central to how comics generate meaning beyond what's literally drawn. Takeaway: the blank space between two panels is doing real narrative work, and which transition type you choose changes what work it does.