I think I'm going to let you figure this out this time around. You're going to use one panel of wallpaper/fabric per bookcase bay
However, to make your life easier, I would recommend you reconsider your selection and use Peel and Stick removable wallpaper that looks like fabric. They sell this through Home Depot
https://www.homedepot.com/p/NuWallpaper-30-75-sq-ft-Ramie-Linen-Peel-and-Stick-Wallpaper-NU2496HD2/302183070
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