wrote:

But what has always mystified me is why some stamps, particularly from
the Eastern Bloc, were issued both ways? Did anyone really go into a PO
and say: "Give me a sheet of imperfs, please, I need to exercise my
scissors"?

:-)

I suppose it was just for those crazy collectors interested in yet
another variety ... and the post office meant to get some more income
out of them. In the case of Hungary, the catalogs say that the
imperforate varietes issued after WW II weren't valid for postage at
all at first. Later on they were, but they were only sold for several
times their denomination.

As for ungummed stamps, some countries issued them this way because
of the humid climate; I believe that e. g. China issued stamps both
gummed and ungummed, the latter probably for use in the south-eastern
parts of the country.

Jan-Martin