In addition to the standard two-dimensional black-and-white, sepia, color, scenic or funny-picture postcard on card or linen, the world of deltiology is filled with some fascinating novelties. Some are made of an unusual material, such as copper, cork or leather, while others may exhibit such embellishments as embossing, embroidery, appliques or woven silk squares.
Even more interesting to the collector are postcards that display mechanical or optical effects. One of the most sought-after types is the hold-to-light card, which, as the name suggests, when held up to a light reveals a hidden image. There are two main subtypes in this category, the first being die-cut examples, where several layers of paper are molded together. The top layer has small shapes or holes punched through that surface only. When held up to a light, these cut-out windows glow with the illuminated color of the paper underneath.
A variant of this, called silver, was made by Samuel Cupples for the 1904 St. Louis World's Fair, showing concealed orange and yellow details against a silver background. The second variety of hold-to-light postcards is known as transparencies. Not as thick as the die cuts, they contain several layers of very thin paper bonded together to form the card, the concealed inner layers containing an additional image that can only be seen when held to a light.
There were also fluorescent cards painted with a substance that reflects light, especially in the dark, making it the opposite of the strict definition of hold-to-light. Joseph Koehler published some of the finest die-cut hold-to-light views, while Meteor and Cosmos were two companies that specialized in transparencies.
Cards with moving parts, called mechanicals, fetch high prices when they are in working condition. The more complex the action involved, the less likely they are to have survived intact, and so finding one with all its working parts is a collector's dream. Simple examples might utilize a silk ribbon or paper tab that, when pulled down, lifts the design from the back. Others might affect color changes via the rotation of a hidden wheel.
Revolving wheels were used to reveal other pictorial elements. A fairly typical early mechanical card might be one in which a window shade can be opened to reveal a kissing couple. Pop-ups are also included in the mechanical category.
Cards featuring an image that morphs into something quite different from what first meets the eye are referred to as metamorphics. More specifically, they often refer to cards in which the face of a famous royal or military figure, such as Napoleon or Bismark, might be, on close observation, composed of a bevy of nude women. Puzzle cards are another form of optical trickery. In these, when the card is turned from one side to another, a different image is revealed. There were other uses of the term puzzle cards: more literal jigsaw puzzle cards, sold in envelopes containing a regular postcard and puzzle pieces; cards issued in three or more installments, where the recipient was challenged to guess the final image; and postcards of the different states, scored to create puzzles.
A very distinctive kind of novelty postcard is known as wire tails, another self-descriptive title. These feature animals sprouting tails made of fine, tightly coiled wire with a springy, Slinky-type action that gives them the appearance of movement. In the early 20th century, these were sometimes used for political purposes. Among the most desirable of these are a Bull Moose Party Theodore Roosevelt card of 1912, and another of Missouri Democratic hopeful Champ Clark made the same year.
Another species of animated animal cards had moving eyes, an effect created by plastic bubbles surrounding the eyes, under which there were beads or discs that moved when the card was shaken.
Linda Rosenkrantz has edited Auction magazine and authored 15 books, including "The Baby Name Bible" (St. Martin's Press; www.babynamebible.com). She cannot answer letters personally.
© Copley News Service