For internal corners, start by pasting the wall into the corner and a little way around. Match up the left edge of the wallpaper and brush it into the corner and around it. It may be that the corner is not perfectly vertical – you’ll only need to go around the corner with the paper by approx. 2-3cm or until the wall is vertical again.
As per our step-by-step guide, the first sheet of wallpaper should have been hung 40cm out from the corner, so do the same here (or match up to that line) and overlap the paper. It’s perfectly fine for the paper in the corner to overlap and, though it could be left to dry, for a professional finish you should take a very sharp or fresh blade, along with a steel straight-edge, to cut the papers where they overlap. Remove the excess off the top paper, then peel the top paper back and remove the excess of the bottom paper.
Next, push the top paper down: it should match and meet perfectly with the bottom paper and join like two seams of wallpaper. (This is why it’s a good idea to overlap in a corner, so any potential mismatches don’t show!)
As for external corners? When you hang the paper to the wall, wrap it around the corner. Again, the wall may not be “true”, so some overlapping may be required – in which case, follow our instructions above to ensure that the overlap in not in sight, but around the corner instead.
How do I tackle plug sockets and fittings?
Start by unscrewing and removing the outer casing of the socket or switch. Apply the sheet of wallpaper as normal and let it hang over the socket area. Next, use a knife to slice a cross-shaped opening, diagonally from corner to corner across the socket area, then cut away the excess. Smooth the paper down with a brush or sponge before reattaching the front cover of the socket.