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Zimochrome
Zimochrome is a trade name for the tinted halftone postcards printed in line block published by H.G. Zimmerman & Company.

Zincography
Zincography was an early form of photolithography designed for use on metal plates. A zinc litho-plate was first coated with a mild acid solution that caused hygroscopic salts to form across its entire surface. A photosensitive asphaltum varnish was then applied and the plate was exposed to a positive transparency. All areas that were exposed to light would harden, and a bath of acetic acid would wash out the rest of the asphaltum. Salts deposited by the original etch were also washed out at this time, except where they were trapped under the hardened areas. The plate would then be coated once more, only now with a dark lacquer varnish (fuchsine). When washed clean with solvent, the lacquer would only continue to stick to the areas where the sensitized asphaltum had hardened. When dampened and rolled with ink the salted areas would hold water and repel ink while the remaining lacquered coating repelled water and attracted ink. As the use of litho-stones diminished, the term zincography was largely forgotten and work printed from photo generated litho-plates, now largely aluminum, is simply referred to as photolithography.

Zip Code (Zoning Improvement Plan Code)
A Zip Code is a series of designated numbers added to the address on correspondence to aid in sorting and speed of delivery. As mail volume increased and service became less personal, the U.S. Post Office Department found its ability to match address to location ever more difficult. After Germany started coding their mail in 1941, the United States came up with its own two-digit zone number system in May of 1943. It did not take long for this simple system to grow inadequate. A whole new distribution system was then developed based on a five-digit number added to the address. Zip Codes would make use of new sectional mail centers set up only for sorting. The first digit represents a basic geographical area within the United States. The next two digits designate a population center such as a city or one of the newly created postal sectional centers in more rural areas. The last two digits designate specific small town post offices or postal zones within cities. This system was instituted on July 1st, 1963 and remained voluntary until 1967 when sorting requirements began to be imposed. In 1983 ZIP+4 was introduced adding an additional four numbers onto the ZIP code. The 6th and 7th numbers are a delivery sector, which can be a group of streets, or a single high-rise. And the final two numbers are a delivery segment, which can be as small as one floor of an office building.


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