Do I have to remove the old wallpaper before wallpapering?

For a perfect result the old wallpaper must first be removed. Only when the substrate is clean, dry, weight-bearing, smooth, absorbent and of a uniform light color, will the result be perfect. To prevent color irregularities in the substrate from coming through the wallpaper, a smooth underlay wallpaper, also called background fleece, or a maculature wallpaper can be applied before wallpapering.