I want to paint over some vinyl wallpaper, the general advice is best not to do it, but my local wallpaper specialist says try it and see, but using vinyl matt or vinyl silk emulsion, if it bubbles then I will have to strip off the paper, if not then jobs a goodun'. The question is, is Dulux standard matt or once emulsion a 'vinyl' emulsion or not, I seem to remember 'vinyl' matt and 'vinyl' silk terminology used to appear on all cans of emulsion paint, now is it just that the word vinyl has been dropped or has the paint changed??

Dulux vinyl matt emulsion is what you're after.....best to use a coat of this first, even if you want to finish it in silk, as the matt is better as a base coat. You may well get some bubbling, but wait a couple of days, and it may well drop back again.