I'm trying to remove some wallpaper in the kitchen for our remodel. The house is '57, plaster walls, and I believe this paper is maybe from the early 80's? Just a guess.

The decorative part dry-peels off, and I'm using a steamer to scrape away the backing (the beige stuff in the picture). Behind that, though, is this linen-textured, white top coat that can peel off all rubber glue-ish to expose the pink stuff. The pink is exposed in places just from scraping the beige backing with a putty knife. Behind the pink is teal, and behind that, I believe, is the plaster wall.

I think this white/pink/teal stuff is all one thing... maybe liner or sizing? Or possibly part of the plaster itself?? It's crumbling in places, scraped to the pink layer in others, but is otherwise very difficult to get off an I'm not sure how to deal. The eventual goal is to be able to paint this wall. Anyone know what this is??