The problem - transparent surface
Flizeline wallpapers use flizeline as a backing, which differs from paper backings in that it is more transparent. This means that the light transmission will be lower for flizeline wallpaper than for paper wallpaper. For this reason, it is important to pre-paint the substrate with a white pigmented primer. Do not use dispersion paint for this purpose as it will block the surface.
The reverse side of our Annex describes the sequence of steps in point 2: "The surface colour must be neutral, otherwise use a white pigmented primer."
When using paper wallpaper on a prepared surface, priming is also recommended as it provides a good base for adhering the wallpaper, strengthens the surface and regulates moisture absorption.