I've always been pretty relaxed about using blutack on walls, but white tack has left some horrible wet-look dark marks on our standard Dulux Matt emulsion.
Any top tips for overpainting successfully? I want to use Endurance/diamond paint next time but do I need to treat the marks so they don't come through again? Google has a variety of ideas from doing nothing, through putting a barrier on like stain stop, to removing the marks with meths which would take ages.
Also I have knotting solution in the shed. Could I use that instead of buying stain stop?