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#55299 - 01/28/03 02:34 PM A method for detecting alterations -- using a UV source or "blacklight"
MW1
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Registered: 07/30/02
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This was a topic on the comic forum, but I think it's also quite pertinent here. There was some concern among the comic denizens over the adequacy of a UV source in detecting color touches (CT's). Apparently this is a big problem with many different titles. Here is a brief summary of some of the concerns:

I've been using a black light on and off for about the last year. There are two problems I've found with using them:

  • They don't seem to be useful unless you're in a dark room. The example someone gave of looking dumb by whipping out a black light at a show--I don't think that's a concern, because even the dim lighting at most hotel convention rooms is too much light to allow you to use the black light effectively.
  • A longwave UV lamp is NOT a magic tool that makes color touch detection easy. Very slight CT doesn't just jump out at you, even under a black light. You've gotta look really closely--the CT doesn't glow like the sun or anything.

It was also noted that UV sources or blacklights can't detect black CT's.


These were some of my thoughts on the topic:

Some of the lower quality UV sources (even longwave) do not perform particularly well. I use a UVP Mineralight Lamp (Model UVGL-58). It's a multiband UV source (115 V, 60Hz, .16 amps) that operates at 254/366 NM in the UV spectrum. I purchased it from the same catalog that university physics and chemistry departments use.

Link to UVP's website

Link to UV lamp section

Using this blacklight source, I can easily detect any material alteration, no matter how small. I can also discern many chemical additives and any CT, no matter how minor. And even though black CTs do not fluoresce like other colors, they are still detectable since they often will reflect light differently.

Still, several other forum members are correct -- there is no substitute for experience, and such knowledge allows for the more effective use of any UV source.

Model UVGL-58 pictured below



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#55300 - 01/28/03 02:48 PM A followup [Re: MW1]
MW1
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If anyone is interested, I could try to take a picture to show how the altered part of a baseball card fluoresces when exposed to UV light. I'm not sure I'll be able to do it, but just let me know and I'll try.
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#55301 - 01/28/03 02:52 PM Re: A followup [Re: MW1]
vayank
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Registered: 04/13/02
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MW > Are these lights the types you find in the classified section of High Times?
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---- Matthew T. Natale Alexandria, Virginia Completed 1977 Topps Baseball SGC Graded Set, Average Grade 92.89

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#55302 - 01/28/03 02:53 PM Re: A followup [Re: vayank]
vayank
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Registered: 04/13/02
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I would like to see such a demonstration ...
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---- Matthew T. Natale Alexandria, Virginia Completed 1977 Topps Baseball SGC Graded Set, Average Grade 92.89

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#55303 - 01/28/03 03:35 PM Re: A followup [Re: vayank]
Lothar52
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Registered: 08/23/02
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i second
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I love CAKE....

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#55304 - 01/29/03 01:36 AM Re: A method for detecting alterations -- using a UV source or "blacklight" [Re: MW1]
aconte
Bid more or post more... tough one...


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I'd like to see a demo.

And I must say I'm glad you post on this board. These are great threads to read
and learn from.

aconte
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#55305 - 01/29/03 02:04 PM UV demo [Re: aconte]
MW1
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Here's the image of a well-known football card illuminated by a high-band UV source in a dimly lit environment. Note the difference in luminescence between the greenish-gold and blue areas of the background. Also, observe the difference in various areas on Lansford's hand and in the name and team banner near the bottom (the dark area is not a shadow). The darker areas reflect (no irony intended) an unaltered status, while those that "glow" indicate a non-original surface (e.g., re-coloring or chemically treated).

Under typical, non-UV lighting, this card appears completely normal -- even under close visual inspection.


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#55306 - 01/29/03 02:12 PM Re: UV demo [Re: MW1]
Lothar52
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Registered: 08/23/02
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nice!!!!!!!!!!!
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I love CAKE....

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#55307 - 01/29/03 02:58 PM Re: UV demo [Re: MW1]
Arty
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Registered: 11/10/02
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Could you post a picture of this card under typical lighting. I think they would also like to see those pics on comics board.
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#55308 - 01/29/03 03:22 PM Visible light demo [Re: Arty]
MW1
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As a footnote to my previous post, I would like to point out that the UV demo you see does not adequately reflect the high degree of contrast present between altered and unaltered areas of the card. An in-person demonstration would be far more effective.

Here is an image of the same card under normal lighting conditions (Note: this card has been professionally restored by Dick Towle of Hammond, New York (Gone With The Stain)).


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