Using a Black Light to Examine Antiques

When you’re in the market for antique or vintage items, you know that there are all kinds of ways unscrupulous dealers can misrepresent the items they have for sale. Both the age and condition of antique items influence their value heavily, but neither is always easy to fully determine through a visual inspection alone. Examining an item under black light is a simple step that can reveal useful information about an item you’re considering purchasing.

Black lights put out ultraviolet radiation. While this wavelength of the electromagnetic spectrum is not visible to the human eye, when it reflects off of certain materials it produces light that we can see. Thus, it can make previously hidden repairs or touch-ups more visible. Also, some specific examples of antique items are known to glow in certain colors in ultraviolet light, while modern reproductions of those pieces do not. Here’s what a black light examination can tell you about these types of pieces:

Porcelain: Expert repairs on a piece of fine porcelain may not be visible, but the modern glue used will fluoresce under a black light, making the extent and location of the fix apparent. Modern paints used to touch up faded designs or details will fluoresce as well. Black light can also help distinguish between hard paste and soft paste porcelain pieces, because the former will glow deep blue or purple, while the latter will glow white.

Glassware: Certain types of glassware will glow under a black light, which can help establish the authenticity of a piece. For example, both green Depression glass and Vaseline glass contain uranium oxide, which will cause them to fluoresce. It’s best to do your homework in advance to determine whether the type of piece you’re considering is expected to have an established fluorescent effect under black light, as the lack of one in that case can quickly reveal a reproduction being marketed as the real thing.

Cast iron: In the 1900s, many interesting pieces were made of painted cast iron, including mechanical toys, banks, and door stops. These can be quite valuable when found in good condition with their original paint. However, there are many reproductions of these types of pieces on the market as well, and it isn’t always easy to tell the difference. Modern paint and glue will show up under a black light, revealing touch-ups, repairs, and outright fakes.

Ephemera on paper: Paper products—think baseball cards, posters, postcards, photos, etc.—from before the 1930s rarely glow under black light. In the 1940s, however, paper manufacturers started widely using chemicals called “optical brighteners” to make their paper look whiter, which means that modern paper generally glows under UV light. This can help distinguish an original from a reproduction.

Of course, using a black light will not give you all the information you need to know about an antique. Such examinations should be used in conjunction with other information and expert advice before you make a decision to buy. You should also take care to work only with reliable dealers who stand behind the authenticity of the antiques and collectibles they put up for sale.

Auction King offers a wide variety of collectibles and vintage items in different categories for the particular collector. We triple-check the authenticity of every item on our site so that our clients can bid with confidence. Register today for a free online account to find your next treasure.

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