I know this question has been posted a couple times but I didn't see any answer to my particular situation so apologies for any duplication. I've just bought an old house and every room is filled with (vertical) lining paper. There are gaps between the paper that I want to cover up. 1 room has newly hung lining paper. My plan is to prime, fill gaps with red devil, sand, another white coast then paint my 2 coats of dark emulsion. Rest of the house has lining paper that has already been primed and panted with emulsion. Plan is to fill gaps, sand and then 2 coats of emulsion. Couple questions: 1. On the walls already painted, should I paint the whole wall white after filling the gaps or can I go straight in with my emulsion after painting? 2. Is red devil the correct/best thing to use here? I saw a couple of posts saying they painted many, many coats and they could still see the filler... is there a better brand/some method I'm missing here? I've also seen online that I could use drywall filler instead which would cut down. Any advice in general for this process would be great - thank you!