I have spent the weekend failing to remember the name, so I've just gone and checked my college notes: Bondina, and having seen the prices I now see why were were encouraged to re-use it to death.

Shepherds is probably your best bet for retail quantities, esp if you're in London, although everything they sell is a bit overpriced. If you just want a sheet of it, though, I can have a look: I think I have some more. It does last quite a long time.