Wallpaper
Wallpapers are not recyclable because they are not pure paper; they contain plastic, synthetic textile fibers and so on. Wallpapers that have been removed from the wall contain traces of plaster and glue, which also becomes a reason why it cannot be recycled. You should dispose of them in the regular trash/compost.
If you are considering removing your wallpaper, you can also paint over them instead to avoid creating trash.