Originally, the walls in this West U. living room were smooth and painted. I didn’t notice anything or any stains when I started priming the walls. But almost immediately after the wallpaper primer was applied, I saw some brown stains work their way through the primer. The wall paint must have sealed them adequately, or perhaps I just had not noticed them, but something about the wallpaper primer activated the stains and brought them to the surface.
A large, old (antique) piece of wooden furniture had sat against this wall, and probably leaned against it. I figure the stains are from either wood sap (yes, even after decades) or from oily furniture polish that came into contact with the wall.
Either way, these stains could work their way through the new wallpaper, just as they had worked their way through the primer. They needed to be sealed with a stain blocker.
Many people use a shellac-based stain blocker, like BIN by Zinsser. But I like KILZ Original, the oil-based version (not the newer water-borne).
Once I applied the KILZ to the stains, they did not reappear. Now I am good to go to get the paper up!
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