Machin Definitives - Testing and Trialling
First released to the public in 1967, the Machin definitive series is now 50 years old. That period has seen enormous sociological and technological change, which in turn has driven continual developments to the Machin stamps. To address the entire lifespan of such development would take far more pages than are available in this exhibit. As such, the aim of the following fifteen pages is to provide a potted view of some stages of the design and production of the stamps from the perspective of pre-release tests and trials, noting where these led to changes in the released stamps.
For clarity, tests are defined to be activities carried out to ensure machinery is working as expected or to ensure layouts or impressions of planned stamps is correct. Trials on the other hand are activities intended to try out a change to the design or technology in use or to determine if a part of the production process can be improved. Trials can therefore exist at several stages in the life of particular stamp concepts. Some never make it as far as full production for public consumption, whilst others might see limited releases.