Cracking paint on wall when dry

[wmcowheads]

Apologies if this has been covered before but I could't find a similar post.

We have just painted our hall and in some areas the paint has cracked when it has dried (the dreaded square cracks).

The paint was over wallpaper which has been painted previously. The cracks only appear in some areas the rest is fine.

Any help would be greatly appreciated

PS we did try a second coat but that came up the same

Help please

 

[joe-90]

It's caused by the wallpaper paste being reconstituted. Best bet is to go over it with oil based undercoat first.

 

[wmcowheads]

The wallpaper has been up at least 5 years and been painted previously .

We have been advised that it mayge due to Matt paint being used on top of silk could thi be the cause

 

[sparkwright]

Was the surface dirty or greasy where it's cracked?

Was the paint allowed to dry between coats?