Wallpapering Tricky Spots: Corners, Archways, Windows & Power Points

Flat wall in the middle of the room? Anyone can do that. The spots that decide whether a wallpaper job looks professional are the corners, the archway, the window reveal and the power points. Here's how to handle each — and none of them are as scary as they look.

Internal corners (the standard case)

Never fold a full strip through an internal corner — walls are never perfectly straight, and the fold will track the wall's error across the next wall. Instead:

  1. Measure from the last strip to the corner at the top, middle and bottom. Take the widest measurement and add 1–2 cm.
  2. Cut your strip to that width and hang it, turning the extra 1–2 cm onto the new wall.
  3. Start the next wall with a fresh plumb line, overlapping the turned sliver. The tiny pattern loss in the corner is invisible; a creeping lean across the next wall is not.

Corners that aren't square

Older homes especially — if the corner is visibly out, the method above is your friend: the overlap absorbs the error. The key habit is re-plumbing at every corner (a plumb line or laser level resets you to true vertical) rather than trusting the previous strip. Wallpaper follows gravity, not your architrave.

External corners

Wrap the paper around an external corner by at least 2–3 cm — never end a strip exactly on the edge, where it will fray and lift. If the corner is badly out of plumb, wrap, then re-plumb and overlap just as with internal corners.

Archways

  1. Hang the face wall first, letting the paper overhang the arch opening.
  2. Trim the overhang back to about 2.5 cm and snip small V-shaped notches along the curve so it turns into the arch without creasing.
  3. Smooth the tabs onto the inside of the arch.
  4. Cut a strip the width of the arch return and apply it over the tabs, covering the inside of the archway in one clean band. On a bold pattern, consider a plain co-ordinating colour for the return — it always looks deliberate.

Windows and door frames

Hang the strip over the frame, then cut diagonally into the corners of the frame at 45° so the paper lies flat, and trim along the architrave with a sharp blade against a scraper. Change blades often — a dull blade tears damp paper.

Power points and switches

Turn the power off at the box first. Loosen the cover plate, paper straight over the opening, then make a small X-cut over the point, trim to just inside the plate outline, and screw the plate back over the edges. Clean finish, no visible cuts. (Never paper over an opening with the power live — damp paste and electricity don't mix.)

For the fundamentals — plumb lines, pasting, seam technique — see the full How to Hang Wallpaper guide.

Still unsure? Order a $10 sample, or email us at mary@wallpapertrader.com — we're happy to help you get it right.