Hi, I'm going to be wallpapering our wall but need some advice on preparing the wall. It's quite high and has an unfortunate defect that appears to be where the plasterboard slabs meet there is a slight bulge. Photo attached to give better idea of what I'm talking about. What would be the easiest way of solving this? Thinking maybe sanding and a bit of plastering either side to try even it out. It will very likely be visible through the wallpaper
