Pattern Repeat and Match Types Explained
Keeping paper plumb in a house where nothing is square, marking a line on every wall, measuring corners at three heights, and deciding in advance where the discrepancy goes
Hang every length to a plumb line you have marked yourself, mark a fresh line on every wall, and measure corners at three heights before cutting. In an old house nothing is square, and the job is not to correct the room. It is to keep the paper true and put the discrepancy somewhere nobody looks.
Period properties are where our designs tend to end up, and they are also where walls lean, ceilings sag and corners open out towards the top. All of it is workable.
Why walls are never straight
Floors settle, timber moves, lath and plaster follows the frame it was applied to, and skirtings and ceilings were fitted to whatever was there at the time. A wall can easily be 15mm out of plumb over its height without anyone noticing, until a patterned wallpaper puts a set of straight vertical lines against it.
The paper reveals the room. That is not a fault in the paper, and no amount of care in hanging will make an out-of-true wall square.
The rules that keep you straight
- A plumb line on every wall. Marked with a level or a laser, not carried round a corner.
- Never hang to an edge. Not a corner, not an architrave, not a chimney breast return.
- Measure corners at three heights, top, middle and bottom, and cut to the widest.
- Check every third length against the level as you go, so you find drift while it is still a millimetre.
When the ceiling is not level
A sagging or sloping ceiling puts you in a genuine conflict: the paper can be plumb, or its top edge can follow the ceiling, but not both.
- Hang plumb where the design is dense, floral or textural. The eye reads the ceiling line as the ceiling's fault, and the trim line simply widens gently across the wall.
- Split the difference where the design has a strong horizontal element or a regular repeating band. Hang slightly off plumb, by half the ceiling's error, so neither the pattern nor the ceiling line looks obviously wrong.
- Never follow the ceiling exactly on a patterned paper. It throws the whole design off vertical and the error grows across the room.
When a corner opens out
Measure at three heights and cut to the widest measurement plus your 1cm turn. The narrower end of the length simply turns slightly further round the corner, which is invisible. Cutting to the narrow measurement leaves a gap at the wide end, which is not.
If a corner is badly out, more than about 2cm difference over its height, turn a smaller amount, hang the next wall to a fresh line, and let the overlap in the angle be slightly wider.
When the wall bows
A gentle bow is not a problem: the paper follows the surface. What you cannot do is bridge a hollow. Smooth the paper into it rather than across it, or it will bubble there as it dries.
A pronounced hollow or a proud patch should be filled or eased before you start. Run your hand across the wall with your eyes closed; that is a better survey than looking at it.
Where to put the discrepancy
Every papered room has one join that does not match and, in an old house, one corner where the plumb line and the wall disagree most. Decide before you start where those will be:
- Behind the door.
- In the corner furthest from the window and from where people sit.
- Above a doorway, where a short length hides it.
- Never on the chimney breast, and never on the wall you see first from the door.
If you have already drifted
If the pattern has visibly run uphill by the fourth or fifth length, it cannot be corrected in place. Take back the lengths that have drifted, mark a fresh plumb line, and re-hang from there, which is one more argument for an extra roll.
Catch it early and you lose one length. Carry on and you lose a wall.
How do I hang wallpaper straight?
Mark a plumb line on every wall with a level or laser and hang every length to it, checking against the level as you go.
My walls aren't straight. Can I still wallpaper?
Yes. Most older houses are out of true and are papered successfully every day. Keep the paper plumb and put the discrepancy where it will not be looked at.
Should the paper follow a sloping ceiling?
No, not on a patterned design. Hang plumb, or split the difference if the design has a strong horizontal element.
Why is my pattern running uphill?
The first length was hung to a corner or a frame rather than a plumb line, and each length after it inherited the error.
Can I correct drift without taking the paper off?
No. Re-hang from a fresh plumb line, losing as few lengths as you can.
How much out of true is normal?
10 to 15mm over a wall height is unremarkable in a Victorian house.
