The surface must be dry, stable and free of dust and grease. Remove old, poorly adhering wallpaper and distemper with baufan® wallpaper remover. Repair cracks and holes with baufan® interior filler. Highly absorbent, sandy and chalky surfaces must be professionally pre-treated. Water-soluble impurities in the substrate that could penetrate during wallpapering should be treated with baufan® Aqua Deck Insulating White. For very translucent wallpapers and high-contrast surfaces, we recommend a primer coat with baufan® wallpaper primer white. To make it easier to change wallpaper later, it is particularly recommended to coat the surface with baufan® wallpaper change primer, especially for washable wallpaper. In principle, critical substrates (e.g. weakly absorbent substrates), surfaces treate.