Webtoon is a digital comics format that is defined by its unique reading mode. Webtoons were designed for mobile phone screens, and are primarily read vertically as a single "strip" of content with no defined page breaks. The format has grown in popularity, particularly in countries like Korea and Japan, where publishers have adopted or wish to adopt the format for their content. Variants of Webtoons are published today either through specialized applications, or on standard EPUB reading systems like Apple Books or Amazon Kindle in Japan.

(See also the material of a breakout meeting at TPAC2024 on the economics importance of Webtoon and, in general, Manga/Comics publications for the Publishing Industry around the World.)

EPUB3 already has the concept of scrolled continuous content, but this feature was considered only for reflowable text-based content, not fixed-layout image content. To make webtoon content work in EPUB, changes need to be made to the specification.

There has been lots of discussions on this issue starting with an issue raised in 2022. The original thoughts were documented on a separate wiki page, which also led to a GitHub Pull Request. However, this PR was never merged, because it never gained consensus. Instead, discussions continued, yielding a different proposal using a different approach.

An overview of the current status was presented at a Face-to-Face meeting at TPAC2024. This presentation was followed by a Working Group discussion, where the group decided that there is enough material to find a consensus, leading to a standard solution to include this feature into EPUB.