preparation for paining interior walls

[clare19]

I have just stripped the wallpaper on my walls to find it has lining paper underneath, it is in good condition apart from some residue glue - if i wash this off, can i paint directly on top of the lining paper? Also I will need to fill in some holes where picture hooks have been - is this ok to do on top of the lining paper?

[heathfield]

The problem with washing the glue off is wetting the paper too much. This could cause it to swell, and not flatten when it dries, so leaving blisters.
If you fill the holes with, e.g. Polyfilla, you'll get a different textured surface from that of the paper. This will always be obvious, even after painting the walls.
The only way to get a professional-looking finish (apart from fully stripping) would be to fill the holes, then re-paper with more lining paper.

[RATTER15]

If you are careful you can sand down any rough or uneven patches on backing paper with a fine sand paper.

[RATTER15]

and I have used filler on backing paper and sanded it down and it is totally undetectable, preparation is the key to a good job!!