These have been identified by deltiologists and grouped together into what are commonly referred to as eras or periods which describe a postcard's style or method of production.
[3] The golden age of postcards is commonly defined in the United States as starting around 1905, peaking between 1907 and 1910, and ending by World War I.
[7] Privately printed postcards were still allowed but they were more expensive to mail (two-cent postage versus one-cent for government cards).
[24][25] Political hold-ups including concerns by future President James Garfield (the Representative), delayed issuance of the official government postal.
[1] Among the most popular, was Charles W. Goldsmith's set of ten postcard designs (in full color) showing the exposition buildings.
[5] All of the postcards there were printed on plain card stock, so most people assumed they were government-issued postals requiring one cent for postage instead of two.
[5] The U.S. Congress passed an act on May 19, 1898, which allowed private printers and publishers to officially produce postcards, and for them to be posted at the same rate as government-produced postals (one-cent, previously two).
The Universal Postal Congress decreed that government-issued postcards in the United States could contain messages on the address side beginning March 1, 1907.
[7] In line with these changes, the United States Congress passed an act on March 1, 1907, which extended this to privately produced cards.
[5] Other factors included shifts in artistic taste among the public, and the development of a sale and distribution network of jobbers and importers—connecting Main Street America with German printers.
[31][27] German publishers began moving production to the United States shortly after the Payne-Aldrich Tariff Act to keep selling to the American market.
[33] Ultimately, the tariffs contributed to the end of the "golden age" as publishing quality decreased (American technology lagged behind German), and as public interest in collecting waned.
[27] Effects of the tariffs were reinforced by the British naval blockade of German merchant ships at the outbreak of World War I in 1914.
[34] In response to the war-time shortages of ink, and the restrictions placed on importation, American publishers began producing larger quantities of postcards which featured a white border on the edges.
[34] Although these were seen occasionally prior to the war, this design change allowed publishers to save ink and lowered the precision threshold for cutting the cards.
[34] During this period, public tastes had changed and publishers began focusing more on scenic views, humor, fashion, and surrealism.
The rag content in the card stock allowed a much more colorful and vibrant image to be printed than the earlier "white border" style.
Cards printed by Curt Teich and Company typically included production numbers in the stamp box, which can be used for dating.
A partial solution was to combine these dyes with petroleum distillates, leading to faster drying heatset inks.
The quicker drying time allowed these dyes to remain on the paper's surface, thus retaining their superior strength, which give Linens their telltale bright colors.
Its original use most likely came from attempts to simulate the texture of canvas, thus relating the postcard to a painted work of fine art.
[7] The images on these cards are generally based on colored photographs, and are readily identified by the glossy appearance given by the paper's coating.