Apologies, gents, but I think I was a bit cavalier in my selection of the Ebay link in my earlier post. In his video 'Poroldchap' simply called this stuff 'glassfibre tape'. In the video 'comments', however, someone asks what's it called and where can I get it in the UK and Poroldchap replies 'Try reinforced tape on ebay etc'.
While the stuff I linked is glassfibre and said to be self-adhesive I somehow don't think this is what Poroldchap is using. I now think he's using glassfibre parcel tape. I've encountered the latter on parcels and it is indeed incredibly adhesive — when trying to strip it from cardboard boxes, the boxes tend to disintegrate before the tape strips off the cardboard. Trouble is, I can't see parcel tape wider than 1"/25mm.
Sorry, but I think people should hold back from buying this stuff until the situation is clarifed.
Joe