Inflation in the 1970s resulted in
ever-higher postage rates, so in 1977 the British Post Office introduced three large-sized
Machins in denominations of £1, £2 and £5. In the British Philatelic
Bulletin, the Post Office said the new stamps “resulted from pressure from customers,
especially business users posting heavy parcels overseas.” At the same time, the 50p Machin
became a low value and was issued in the normal small size, a fate that earlier had befallen
the 10p and 20p Machins.
The Post Office also noted, “For the first time in the history of
United Kingdom stamps, the high value issue will be printed by photogravure instead of the
traditional recess-printing process.” Although the reason for this change was not given,
it is well-known that photogravure stamps are less costly to produce than engraved ones.
This series was expanded with five additional values to be used on parcels.
The first such value was £1.30 issued on August 3, 1983 and the last was £1.60
issued on September 15, 1987.
These Machins remained in use for a total of 11 years. Then,
in a surprising return to the past, a new set of four recess-printed high values picturing castles appeared in 1988.
The denominations were £1, £1.50, £2 and £5.
In 1995, £1 officially became a low value. The £1 castle
was replaced by a £3 version with the same design (though a different color), and a
£1 small Machin was issued.