Can I apply Terrastone on ingrain wallpaper?

Terrastone can be applied to a firmly fixed ingrain wallpaper, provided that a plaster primer containing quartz has been applied beforehand. However, it is difficult to determine in advance whether the ingrain wallpaper is actually sufficiently fixed or whether it will peel off after the plaster has been applied. The structure of the ingrain wallpaper also impairs the visual result of the Terrastone surface. We therefore recommend removing it in advance.