The infinite canvas is the idea that the size of a digital comics page is theoretically infinite, and that online comics are therefore not limited by conventional page sizes. An artist could conceivably display a complete comics story of indefinite length on a single "page". Scott McCloud introduced the concept in his book Reinventing Comics.
The infinite canvas has been used in comics such as Dominic Deegan: Oracle for Hire, where artists are easily able to change their standard format from one line to two when desired. Likewise, Megatokyo made a smooth transition from traditional four-panel comic strip to full-page graphic novel. Webcomics such as Narbonic take advantage of the medium on occasion for special effects (e.g. the time-shift effect in "Dave Davenport Has Come Unstuck in Time"), and even sometimes use the "gradualism" effect McCloud describes. Even four-panel comics benefit by not having their comics "squeezed" onto a newspaper page to the point of illegibility, and thus can include more detail.
Keeping comics in a more traditional page format eases the writer's transition into publishing their comics in print format, as expressed by at least one writer; and limiting the size of comics makes them more accessible for readers who access the comic not through the regular site but, for example, through RSS readers or the Wii internet browser.