Why would Austria print the same stamp design by 4 different methods?
That's a good question rohumpy.
By 1957 the old costume definitives had been around for almost 10 years
therefore they were due for replacement.
The new building series was developed & designed by Hans Strohofer.
The first stamp issued on June 22, 1957 (Scott 620) was printed recess engraving
(Georg Wimmer engraver)
depicting Mariazell Basilica, the most important pilgrimage destination in Austria and one of the
most visited shrines in Europe.
Since 1957 was the 800th Anniversary of the town's founding the stamp was more or less
a definitive commemorating an event.
But engraved stamps are much more expensive to produce compared to
other print methods, especially when hundreds of millions are required.
The Post Office wanted a cheaper process so the State Printer produced
version (Scott 621) Issued on October 25, 1957.
Apparently no one was happy with this printing especially when compared
to the engraved version.
Therefore it was finally decided to print the low & mid values via lithography (offset)
and only the high values 10S and 20S by way of recess engraving.
version (Scott 622) was issued January 19, 1959.
stamp (Scott 630B) in a smaller format (see below) was issued
on February 1, 1960.
They were produced in coils & sheets for vending machines.
Printing was done by the British printer, Harrison & Sons.