I'm just about to start decorating my livingroom. Currently all walls are papered in a textured paper and painted with a vinyl silk finish, probably looked nice in 1974.One exterior wall appears to have a Warmaline or Kotina type covering, its hard to know for sure as the vinyl silk finish means I can be sure if its polystyrene or just a heavy textured paper. I'm stripping all the other walls and will line with 1200 grade paper, but a bit uncertain about this one. If its Warmaline can I dry strip it? Is this easy. Alternately I could line over it but I've never lined over vinyl silk before, can I just rub it down with a 100 grade sand paper or I have heard its better to paint with a thinned undercoat which then allows the paste to adhered to better. Any thoughts?