Prep for old plaster before skimming

[pilsbury]

I’ve just removed a load of old wallpaper from my walls in a room. The 100 year old plaster isn’t in bad nick but would certainly welcome a skim to sharpen up.

What do I need to do to the walls before hand? Although not obvious, there’s likely to be some paste residue.

Sugar soap wash?
PVA?
Blue grit?
Nothing?

 

[23vc]

Scrape it down, tape any obvious cracks, pva it until it goes tacky, 2 coat skim it.