What is an “original” antique map? How can there be more than one original?

From time to time a customer asks how a map can be an “original” when we have more than one in stock, or when we have another map which is the same or similar, or when he or she has seen the same map somewhere else. Printed maps are created from a single manuscript (literally, hand drawn) map from which the engraver made the block or plate. It could be argued that only the unique manuscript map is the “original”; with a painting, this is clearly true, but in the map trade it has always been the case that any impression made from a particular woodblock, copper plate or steel plate has been regarded as an “original” example of the map, and until that plate or block was destroyed “originals” could be printed from it. That of course means that many “original” examples may exist, although each block or plate has a limited life due to its physical limitations, and only a finite number of prints can be made from it. The number of impressions of a map which can be made from a woodblock is fairly limited before wear to the block causes each printed impression to progressively deteriorate. The longevity of copper plates is greater than that of wood, although being a fairly soft metal it too deteriorates over time. The introduction of the use of harder steel plates for map making in the early 19th century increased the durability of the plates, and commensurately extended the life of the plates and the number of original impressions that could be created from a single plate. For that reason, maps printed after about 1830 tend to be more numerous and common than earlier copperplate or woodblock maps.