Wallpaper can be one of the great mysteries of owning an Android phone. It may not have a lot to do with e-books directly, but it’s one of the big ways of personalizing your pocket pal—and you certainly can’t do that with an e-ink Kindle!
But sometimes it seems as though the way it works doesn’t make any sense. I’m sure it’s happened to almost everyone who owns an Android device at least once: armed with the knowledge of your device’s resolution, you go and seek out an image that exactly matches that resolution, and try to set it as your wallpaper—only to be presented with a cropped-down selector with which you have to choose a subsection of that image.
The reason for this is that Android device wallpaper doesn’t work like the wallpaper on your desktop computer. While desktop wallpaper is a static image, Android wallpaper changes position when you slide from one home screen to another. There are three home screens, and they overlap with each other by 50%. That means that for a wallpaper to be properly-shaped, you have to choose one that is the height of your display but twice the width. So for my 2560 x 1440 Nexus 6, I would need to pick a wallpaper that is 2560 x 2880.
You can generally find some good selections of wallpaper sized to fit your device just by googling the resolution you need plus the word “wallpaper”. (For example, “2560 x 2880 wallpaper”.) The problem high-resolution phone owners like me run into is that while you find lots of attractive generic images, it’s awfully hard to find wallpaper of any specific show or movie in that format. Screen captures aren’t going to be high-resolution enough to crop down to the right size—even a 4K Blu-ray or streaming video is only 3840 x 2160.
Fortunately, it may not be too much of a concern. There’s not a whole lot of noticeable difference between a full-resolution wallpaper and something a little lower on a screen that size—so if you can find a good high-resolution photo that you like, such as some of the digital snaps uploaded to Flickr, then download that and set it as your wallpaper, that will probably be good enough. Just remember that for a portrait-mode phone, you actually need a landscape image in order to get the full height.
For my phone right now, I’m using this image from wildlife photographer “Tambako the Jaguar,” with the framing set so the cub’s head is centered on my left-most home screen and as I swipe right the mother’s comes into view.
Good luck, and happy wallpaper hunting!