Just been looking through some boxes of other peoples
old slides that I bought a few years ago in house
clearance shops.

One box has a mix of slides marked 'made in england'
with no obvious date. I thought Kodak always stamped
or printed the processing date ?. Does anyone know
when this became common practice ?.

In the same box are some Kodachrome slides marked
'made in usa' and these do have a printed date - Aug 61.

The colours are as good as original, by holding them up
to daylight.

Another box has a collection of UK architectural photos
taken on Ilford slide filem and they are very dark.
Either they are badly done slide copies or the camera had
an exposure fault, or maybe Ilford slide film goes darker
blue with age.

Interestingly there are quite a few commercial slides of
USA historical sites, but unlike the classical commercial
slides that turn bright red after a short while, these
still have original colours, possibly Kodachrome though
the slide mount doesn't say so.