Comment by sudobash1

> I think the UK sender didn't need to include _two_ global forevers.

It would be hard to know that ahead of time though. The global forever stamp is good for letters up to 1oz which can be as little as 4 US letter pages. It took the FSF 5 double-sided pages. Granted, it looks like lightweight paper & the post office doesn't seem to be very picky about this. But I think sending two forever stamps was being on the safe side.