Originally Posted by ProfCrash
You can use Comixology on your computer as well so you can have the comics and the app on multiple devices
I think it just streams on the desktop. At least, I couldn't find any sign of a downloaded comic when I went digging. I think you need to download to your mobile device to get a permanent file. The issue I'm having there, though, is the available space on my tablet.
There may be something sneaky I can do, though, to copy the files to a backup on external storage.