Originally Posted by 9littlebees
ADE has a number of "sample" epubs I will try out, I'll obtain some kepubs from the Kobo store, epubs from the WH Smith store (our official Kobo retailer in the UK) and I'll browse the interwebs for some legally free CBR/CBZ and epubs (like the Conan epub I mentioned earlier).
It might also be an idea to download a DRM epub from the Kobobooks.com site. Preferably one that you have the Kepub of too, to compare the two.
For instance, I've noticed previously that book covers of kepubs show up perfectly full screen, no margins. And then when I download the DRM epub of the same kepub and put that on my device (either through ADE or via Calibre with DRM stripped), the same book with the same cover but in epub format suddenly has a cover showing margins (ie. not full screen).
I don't know if this is still the case in the current firmware (I did the above in 1.9.17), as now I change all my stylesheets to show the covers correctly without margins (which needs unpredictable code to work perfectly. Even regular code and/or with proper fixed sizes in for the cover image still gives margins.)