In the first part of this series, we looked how to identify the most common photographs from the 1800s. In part two, we looked at photographs from the early 20th century, in particular, photographs made before 1920. Here, we discuss the use of black lights to identify many fakes and reprints.

For collectors of Pre-World War II paper material - including photographs, sportscards, publications, posters, postcards, advertisements and more - there is a sophisticated yet inexpensive and easy-to-use tool for quickly identifying many modern reprints and fakes. This tool is called an ultraviolet light or black light. While there are many uses for black light in collecting and beyond, this article shows how it can be used to identify modern paper and cardboard.

How Black Light Works
A black light allows the collector to see things not seen under normal daylight. Black light is outside the human's visible spectrum, meaning that it cannot be seen by human eyes. However, in an otherwise blackened room, different materials can fluoresce (glow) under black light. Most of us have experienced black lights that make the whites on our shirts or shoes glow brightly. Some materials fluoresce brightly, some not at all, and the rest somewhere in between. Fluorescence can differ in color. For example, some inks fluoresce yellow, some brown and some blue. The quality of fluorescence happens at the atomic level of the material.

Identification of Modern Papers Using Black Light
Black light is effective in identifying many, though not all, modern paper stocks.

Starting in the late 1940s, manufacturers of many products began adding "optical brighteners" and other new chemicals to their products. Optical brighteners are invisible dyes that fluoresce brightly under black light. They were used to make products appear brighter in normal daylight, which contains some black light. Optical brighteners were added to laundry detergent and clothes to help drown out stains and to give the often advertised "whiter than white whites." Optical brighteners were added to plastic toys to makes them brighter and more colorful. Paper manufacturers joined the act as well, adding optical brighteners to many, though not all, of their white papers stocks.

A black light can identify most cards, posters and other paper items that contain optical brighteners. In a darkened room, optical brighteners will usually fluoresce a very bright light blue or bright white. To find out what this looks like, just shine a recently made white trading card or most types of today's white printing paper under a black light.

If paper stock fluoresces very bright, it almost certainly was made after the mid-1940s. It is important to note that not all modern papers will fluoresce this way, as optical brighteners are not added to all modern paper stocks. This means that if a paper doesn't fluoresce brightly, this does not mean it is necessarily old. However, with very few exceptions, if a paper object fluoresces very brightly, it could not have been made before World War II. I would guess that well over 90% of modern reprints and fakes of Pre-World War II trading cards and photographs contain optical brighteners that can be identified with a black light.

Before declaring objects fakes and making a citizen's arrest on your grandmother, it's important to gain experience. This means using a black light to examine and compare the fluorescence of a variety of items. When examining photographs, make sure you shine the black light on all sides, as some have a coating on the fronts.

The collector should also follow all safety rules for the use of black lights. If used correctly, they are safe, but, for example, the user should not look directly at the light. Boxed black lights should come with directions. It is recommended to buy a longwave black light as opposed to a shortwave black light. Shortwave is important in the examination of some stamps and other objects, but longwave is safer.

Where to Buy a Black Light
Black lights and ultraviolet lights are widely available and have a wide variety of uses. Geologists use them to identify minerals, collectors of glass use them for authentication. They are even used to find scorpions at night. Black lights are sold by many science, hobby and rock stores. I bought mine and tested it out at a hobby store in my hometown of Seattle. Black lights can also be purchased online. I have seen hand-held models offered for well under $20 each at eBay and online stores.

NOTE: Part 1 of this series can be found online at http://www.auctionbytes.com/Email_Newsletter/53/53.html#photos. Part 2 can be found at http://www.auctionbytes.com/Email_Newsletter/53/54/54.html#photos.