Most SVMs were positioned in public places to provide a useful service to customers when other sources of postage stamps, such as Post Offices were closed.
The name Stamp Vending Machine only applies to the internal mechanism, the housing is described by the UK Post Office as a "case" and was supplied, installed and maintained separately.
Their design, fairly modern, is similar to the kind of electronic interface you may find on a machine selling train tickets, or an ATM: a screen displays several buying options, possibly in different languages.
The French machine, located in post offices, can let the user weight the envelope so that the exact correct fare may be selected (depending on the destination country).
The German machines, located either inside or outside post offices, don't feature a scale, but the user can type the value they want to see printed on the stamp, before selecting how many they want.
The German machine doesn't give change in coins, but issues extra stamps with the remaining value.
The earliest production series machines were introduced under Edward VII in 1907 following experiments with a patented 1906 design by New Zealander Robert J Dickie which was demonstrated to the British House of Lords in 1907.
4) design of the classic British red telephone box, introduced in 1925, incorporated a stamp vending machine.
It could be set to dispense any number of stamps from one to five against the insertion of a single coin, although in practice this was never done and all Type G machines vended a strip of five values.
Initially set to dispense 4 x 25p stamps in a folded booklet in exchange for a £1 coin, different combinations were later employed as postage rates in the UK continued to rise.
These electro-mechanical machines were powered by large internal battery packs which made them expensive to service and more unreliable than the purely mechanical designs.
As stamp booklets can now be widely purchased from supermarkets, garages, kiosks and newsagents, demand for automatic vending facilities has declined to the point where their continued operation becomes un-economic.
Remaining machines are also found inside Post Offices, dispensing 1st and 2nd class NVI stamps from coils for those customers who wish to avoid queues.