Postcards, sometimes spelled out in two words as "post cards," emerged during the late 19th century as national postal systems began to standardize and improve their delivery methods. America’s first “postal card” was copyrighted by John P. Carlton in 1861, who sold the rights to H.L. Lipman in Philadelphia. Lipman’s Postal Cards were non-pictorial, meaning their front was designed as a blank space for the sender’s message, and the back was printed with an address line and stamp box. In 1869, Austria launched the first national postal card, known as a “correspondenz karte,” already imprinted with paid postage. The idea quickly caught on throughout Europe, with several other countries debuting their own postcards over the next decade. The U.S. government began selling its first postcards with pre-printed stamps in 1873, and in 1875, the first International Postal Treaty was enacted to allow postcards to be sent beyond a country’s borders. Finally, Congress passed the Private Mailing Card Act in 1898, ending the U.S. government’s monopoly on pre-stamped postcards and lowered the standard rate for mailing these cards to a single penny. Postcards boomed in popularity around the turn of the 19th and 20th centuries, particularly as costs were lowered and improved mail service allowed for deliveries multiple times a day: People could afford to send frequent notes to their families, friends, or neighbors the way we might use text messages today. Previously, souvenir photographs and lithographed cards had been sold to advertise tourist destinations, businesses, holidays, and special events, in formats such as cartes-de-visites, cabinet cards, and stereoviews. In contrast to these, postcards required space for a message on the front side with the back reserved for an address and postage. However, in 1907, the United States Postal Service began allowing postcard backs to be divided, including a message on one half and an address on the other. This shift meant that images were suddenly an integral part of postcard design, and cards could be made for every imaginable occasion, theme, or destination. Postcards quickly became an international craze, with early fans collecting postcards relating to pop culture, advertising, specific locations, and many other categories. Artist-signed postcards were especially popular, featuring reproductions of works by artists like Alphonse Mucha, Harrison Fisher, Ellen Clapsaddle, and Frances Brundage. In the late 1890s, Swiss entrepreneur Heinrich Wild established the Detroit Photographic Company (later renamed the The Detroit Publishing Co.) to capitalize on the popularity of Photochrom prints. First developed by Swiss lithographer Hans Jacob Schmid, Photochroms, were printed using a minimum of four etched stones—one each for red, yellow, blue, and black ink, though the process could use up to 14 for more complex coloration. The Detroit Photographic Co. made a deal with American photographer William Henry Jackson to colorize thousands of Jackson’s black-and-white images, working with Jackson’s original watercolor sketches to match the coloring for their postcards, which they called “Phostints.” However, by the 1910s, Photochroms fell out of fashion as offset-lithography ate into the market, eventually leading the company to bankruptcy. One of the Detroit Publishing Co.’s primary competitors was Teich & Co., which began as a Chicago print shop opened by German immigrant Curt Teich in 1898, the same year postcard fees dropped to a penny. However, rather than utilizing the Photochrom method, Teich put his money behind the newer format of offset lithography, which used machines to print from durable zinc plates. Teich developed his own custom offset-printing machine in 1910, which could print sheets of up to 32 postcards at one time. By reducing the amount of black ink used, more of the images were filled in with color, giving Teich & Co.’s postcards a vibrant, almost surreal quality. In the early 1930s, Teich experimented with textured papers to better absorb brighter inks, settling on a format he called the C. T. Art-Colortone, today known as linen postcards. With their exaggerated colors and perspectives, linen postcards resembled tiny canvases displaying a surreal new vision of America. Over the next few decades, thousands of linen postcards were produced by companies including Tichnor Brothers and Colourpicture of Boston, and E.C. Kropp of Milwaukee. As the largest of these publishers, Teich & Co. printed some 45,000 different linen-postcard designs during the 1930s and ‘40s. To date a vintage Teich postcard, look for a number and letter preceding the card’s stock number on the lower-front of the card or running vertically along the center of its back. Decades are denoted with letters (“A” identifies cards made in the 1930s, “B” is for the 1940s, and “C” denotes the 1950s) and the preceding number indicates the specific year within a certain decade. Those beginning with “6B,” for example, were printed in 1946. Large-letter postcards also shined during the linen-postcard era, often imprinted with the phrase “Greetings From” followed by a place name spelled out in oversize lettering. Many vintage large-letter postcards also included small views of a location’s best-known tourist sites within the letters. In contrast to these fantastical views of America, real photo postcards, or RPCs, were popularized by Eastman Kodak, which began selling Velox photo paper printed with a postcard back in 1902. The next year, Kodak released its No. 3A Folding Pocket camera, which used black-and-white film specifically designed for postcard-size prints, thus making more expensive cabinet cards obsolete. By the 1940s, Eastman Kodak had improved its multi-layered Kodachrome slide film, allowing postcards to be made from these color negatives. Known as photochromes or simply chromes, these images were actually printed using offset-lithography plates corresponding to the halftone negatives for each of four colors—cyan, magenta, yellow, and black (CMYK). Antique postcards were also produced in a variety of novelty formats and materials, such as wood, aluminum, copper, and cork. Silk postcards—often embroidered over a printed image—were wrapped around cardboard and sent in see-through glassine paper envelopes; they were especially popular during World War I. Hold-to-light postcards were made by inserting tissue paper between two pieces of regular paper with holes cut through portions of an image, allowing light to shine through and make them glow. Vintage fold-out postcards, popular in the 1950s, had multiple postcards attached in a long strip. Many interested in antique postcard collecting get their start by looking for cards from their hometown or state, and expanding out from there. Postcard collectors often focus on particular themes, like Christmas, Halloween, portraits of movie stars, European royalty and U.S. presidents, wartime imagery, and photos of natural disasters. With old postcards, subject matter, condition, and rarity, plus general desirability and demand, determine value.