Most wallpapers emit an odour after hanging. This is caused by applying adhesive to the wallpaper. This smell will diminish as it dries. Good ventilation and an equable temperature will ensure that the smell disappears completely within a few days. Vinyl wallpaper may also emit a faint smell of vinyl under certain conditions (warmth, poorly ventilated area). There is also no reason to worry about this, as the smell will disappear completely with adequate ventilation. As vinyl wallpaper dries a little more slowly than other wallcoverings, the smell may take a bit longer to disappear.