How to wallpaper around corners, windows and awkward shapes

Flat, unbroken walls are the easy part of any wallpapering job. The corners, the window reveals and the odd cut around a doorframe are where a room is won or lost. Paper never meets a room at a perfect right angle, because rooms are rarely square, and a length carried straight round a corner will show it. The good news is that decorators solve this the same way every time, with a few plain rules. Once you know them, an awkward corner stops being a problem and becomes just another cut.

Why you never wrap a full width round a corner

The single most useful rule is this: don't carry one width of paper right around a corner. Walls lean, and a length that looks plumb on one side drifts out of true on the other, so the pattern tilts and the far edge gapes open. Instead you cut the paper at the corner and start the next wall fresh. You lose a little paper and you gain a straight, plumb run every time. This holds for internal corners, the ones that fold away from you, and external corners, the ones that stick out into the room, though the method differs slightly between the two.

Internal corners, measured and cut

Measure from the edge of your last full length to the corner at the top, the middle and the bottom, because the gap will vary. Take the widest of those three figures and add about 15mm. Cut your next length to that width and hang it so the small extra turns onto the second wall. Smooth it into the corner with a paperhanger's brush, then snip the top and bottom so it sits flat without creasing. Now hang the offcut on the second wall. Plumb its leading edge with a spirit level or a chalked line, not off the corner, and let it cover the little turned overlap. On a busy pattern the join all but vanishes. On a plain or geometric paper, keep that overlap tight so the double thickness doesn't cast a visible line.

External corners, wrapped a touch further

External corners, like the front edge of a chimney breast, take more care because they catch the light and the eye. Turn the paper about 25mm round the corner rather than cutting it flush, so there's no raw edge sitting on the most visible part of the wall. Then hang the next length over it, plumbed as before, so it laps the turned edge. If the paper is thick or the corner is truly out of square, a fine overlap wrapped round the angle beats a cut edge every time. Press it down well and wipe any paste from the face before it dries.

Windows and reveals

A window breaks a wall into pieces that still need to line up. Hang the length that reaches the window as if the opening weren't there, letting it lap over the recess. Then cut into it horizontally at the top and bottom of the reveal, so you can fold the flaps back onto the top and the side of the recess. Fill the reveal itself with a matching piece, patterned to carry on from the wall above and beside it. It's the fiddliest part of most rooms, and it's the one spot where a spare offcut from the same batch earns its keep. Keep the cuts crisp with a sharp blade, and change the blade often, because a dragging knife tears damp paper instead of slicing it.

Doorways, arches and other awkward shapes

Doorframes follow the same logic as windows. Hang the length over the frame, then trim it back to the edge by running a knife along a broad filling blade held against the architrave. Arches need the paper cut into small tabs round the curve so it can fold neatly onto the underside without pleating. Sockets, switches and radiators each have their own trick, and we've covered the most awkward of those in a separate guide to wallpapering behind a radiator without taking it off. The principle underneath all of them is the same. Hang the paper past the obstacle first, then cut it to fit, never the other way round.

Habits that make the awkward bits easier

• Keep a sharp blade and swap it the moment it starts to drag. A torn edge on damp paper is what ruins an otherwise clean cut.

• Plumb every fresh run off a level or chalk line, not off the corner or the last length, so a leaning wall doesn't compound across the room.

• Buy a roll more than the calculator says. Awkward walls eat paper, and reveals and arches want offcuts from the same batch.

• Match the pattern at eye level first. A join that lines up where you look forgives a little drift down near the skirting.

• Wipe paste off the face straight away with a damp sponge, before it dries and leaves a shiny mark.

None of this is difficult once you've done it on one wall. Awkward spaces reward patience and a sharp knife more than they reward skill, and a forgiving pattern hides the odd imperfect join far better than a plain one ever will. If you're choosing paper for a room full of corners and reveals, a repeating or mid-scale design is kinder than a large plain field, and paste-the-wall types are quicker to handle when you're folding round a recess. You can see the pattern repeat and the hanging method listed on every design in our wallpaper range, so you'll know what a tricky wall involves before you order. And if lining up the pattern is the part you're unsure about, our guide to pattern matching basics walks through it drop by drop.