wallpaper is a decorating material. It consists of two layers of paper with wood fibre in between; different kinds of ingrain wallpaper are distinguished by the size and form of the fibre pieces.Ingrain wallpaper was invented by German pharmacist Hugo Erfurt
in 1864; marketed by the company his grandfather founded, it was first
used as a decoration for shop windows, but began seeing use as a
wallpaper from the 1920s on as well. Ingrain wallpaper is the most commonly used type of wallpaper in Germany; it is not as common in the English-speaking world. (source: wikipedia)
