I have recently covered over wall panels in my living room. Some panels were removed prior to papering, but some were not. The paper below proved to be really good at covering over the panels. it is really thick, dead easy to use, though does bubble a fair bit when first applied. I don't there is a better paper out there for covering over imperfections. Recommended.
2000 Lining Paper (https://m.media-amazon.com/images/I/61xmPBwJovL._AC_SL1200_.jpg)
Direct link here (https://www.amazon.co.uk/gp/product/B01HR2ZXOG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&irclickid=Wr8V%3ABxA9xyPWMXUVWy2lTICUkHzvj0ZhW%3AEwc0&ref=dmm_asc_ir_4061861_Wr8V%3ABxA9xyPWMXUVWy2lTICUkHzvj0ZhW%3AEwc0&irgwc=1&th=1)