There have been a few works called ''Between the Lines''. The ones with pages here so far are:

* [[Webcomic/BetweenTheLines A web comic]] about a bunch of transgender teenagers.
* [[Series/BetweenTheLines A TV series]] about police InternalAffairs, London style.
* [[ComicStrip/BetweenTheLines A one-panel comic strip]] in the New York Daily News.
* [[Fanfic/BetweenTheLines An fanfiction anthology]] based off of ACertainMagicalIndex.

Alternatively, you may have been looking for artistic meaning that's "between the lines" of a work, i.e. {{Subtext}}.