Can you identify these patches on a wall?

[Galet]

I removed the wallpaper from a bedroom. Everything as usual, just a few patches of plaster needed to be re-done. The area under the bay window was a bit rough, so I decided to use easi-fill. After a day, I noticed that there are some patches coming up... do you have an idea of what they are?

surface seemed sound and dry. Is it possible that an old water infiltration comes back to the surface? It's a first floor bedroom, window facing South, PVC frame and double glazing (not installed by me). The rest of the room has no problems at all.

Thanks, F

[Jonathan]

To me, they look like old water stains. If there is no damp, painting over them with an oil-based paint (undercoat) should stop them reappearing.

Jonathan

[readthisbot]

Glory be! It's the face of the Blessed Virgin!!!

[Galet]

You may be right, I'll check for blood tears tonight... You know, I'm Italian and the Holy Mary could have followed me when I moved here... For the Italian speakers: