Vintage kraft wallpapers are easy to spot. While most vintage wallpaper designs were printed on relatively thin, light in color, and pliable paper, some vintage wallpaper patterns were printed on a thick, dark, almost cardboard-like kraft paper. Today we call these darker, stiffer wallpapers "vintage kraft papers" or "vintage kraft wallpaper," but at the time they were printed, they were known as "decorative building papers".
The two pictures below show the difference between regular vintage wallpaper and vintage kraft paper:
The differences between traditional wallpaper and vintage kraft paper may be obvious (especially if you touch the two types with your own hands), but what's not obvious is the purpose behind vintage kraft papers. What were they created for anyway?