What has caused this 'creasing' on wall? ?

Smithy99

Does anyone know what's caused this? It runs from just under the corner of the window frame across the wall and into the next wall.  Thanks

Smithy99

Hoping it's just one of those things? 

TELLIT01

I would suspect a crack in the wall behind the wallpaper.

grumbler

Or just in the lime plaster. In old houses wallpaper is often the only thing that holds the plaster together and in place.

Smithy99

Thanks.  It's plaster and painted. House is 1970s built, cavity wall (although now insulated) if that helps at all.

thehog

We had a line like that appear on our toilet wall when the bathroom was being redecorated, but it was caused by the tiles being taken off the wall on the other side. Bathroom installer made good with filler and fresh paint. 

frogglet

Looks like a crack under some vinyl emulsion where the paint has just flexed with it.