See the 2 screenshots I posted on the previous page, ProfCrash, in
post #894.
Each of the thumbnails in those 2 screenshots shows a different textured background. Imagine reading your Marvin books with a background like that, or indeed any (photographic) background you yourself prefer. Why not? Someone might even wish to read texts overlaid on a photograph of their beloved (wife, or kids, or house pet) -- again, why not?

Background textures are
standard functionality in many iOS readers, for example in Stanza, which comes preloaded with several of them. It would be wise for Marvin to follow Stanza's example in this area, too, as it has usefully done in so many others.
Kris has already confirmed background textures will be possible in future in Marvin, so the only question now is how to implement them optimally. And I believe the optimal way for Marvin would be to come preloaded with 12-15 nice background textures, to showcase this particular aspect of functionality,
plus give users a button to integrate an unlimited amount of
custom background textures, simply by picking them from the Photo app's Camera Roll or any other album there.