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Ultraviolet Light and Black Light: a beginner's guide
by David Rudd Cycleback


1) Introduction

2) What is ultraviolet light?

3) The different kinds of UV light

4) Your tool for this guide: a black light

5) Where does ultraviolet light come from? How was it discovered? Why can't we see it?

6) How are black lights made?

7) Practical and interesting uses for your black light

8) Examining art and collectibles: Introduction

9) Identifying modern fakes of antique paper memorabilia

10) Identifying counterfeit US currency

11) Identifying alterations to art, collectibles

12) Examining cloth

13) Examining art glass

14) Making glow in the dark art and crafts

15) Protecting yourself from the Sun's UV

16) UV light in science and industry

 

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Identification of restoration in art and collectibles

Black light is helpful in identifying many types of restoration and alteration to paintings, prints furniture, photos, vases and more. These items can be altered by the addition of paper, glue, paint, varnish and/or other material. Items are typically restored to fix damage and make things appear new.
As the added material often fluoresces differently than the rest of the item, the restoration can often be identified under black light.

To identify alterations, one should also look for differences in texture, gloss, and opacity. When an art print is put at an angle nearing 180 degrees to a light, the added paint, ink or paper will often have a different texture and gloss from the rest of the card surface. The added material also may be physically raised from the rest of the surface. You might be able to feel the relief with your finger tip.

added pain on an altered baseball card, easily identifiable at sharp angle to desk lamp

Opacity is the 'see through' effect when you hold an item up to a light. If material is added to a poster or print, it will often appear darker than the rest of the translucent collectible.

The backs and insides of items often reveal restoration-- for examples, the back of a pin may reveal solder and the inside of a desk drawer may reveal the original color.

As restoration and alterations can effect financial value, the presence of known alterations must be revealed at sale. A mint condition movie poster is worth more than a low grade movie poster restored to mint condition. Not disclosing alterations at sale is unethicall and might be considered fraud.

Some dealers and collectors remove autographs from baseballs for aesthetic or financial reasons. For example, a single signed Joe DiMaggio baseball can be worth more than the same ball with the bat boy's signature beneath. There is one or more companies that will remove autographs. While the removal may be difficult to see under normal daylight, the restoration shows up under black light.

In some cases, forgeries are alterations. For example, a inexpensive baseball card may be changed into a rare and valuable variation by changing text. In the earlier mentioned drivers license forgeries, the forgery may be a genuine license that has had the name or age altered with paper and glue. Many kids want their license to say they're old enough to drink. In many cases, these changes are identified by the above mention techniques.

In a few cases, the forger covered the entire baseball card in a clear substance to try and cover up the handiwork. The substance however gives the card a different gloss and black light fluorescence than other cards in the issue. A collector didn't notice the actual altered text of one card, but noticed the card had a distinctly different gloss than his other cards from the same set. Closer examination by an expert revealed the alteration.

metal figure with clear tape that shows up under black light

The back of an old photo shows old adhesive under black light

 

Next: Examining cloth

 

 

 

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