Friday, May 22, 2009

Watermark Detection - Yesterday and Today

Leland Bell, a retired Louisville chemist who has collected stamps for 70 years, is featured in a USA Today article about carbon tetrachloride.

According to the piece by reporter James Bruggers, "For much of the 20th century, carbon tetrachloride was regarded as a miracle chemical: It was used to put out fires, degrease machines, kill bugs, dry-clean clothing and even help stamp collectors detect forgeries. From the mid-1960s through the mid-1980s, most of those uses were discontinued for health and safety reasons."

Leland,a retired Louisville chemist shown above, recalls how it helped reveal authenticating watermarks. "You'd put the stamp facedown in a little black tray, and put a few drops of carbon tetrachloride on," he says in the article. "We really didn't give it much thought."

Today, there are much safer and environmentally friendly ways.

According to the 1847usa Web site, "There are many ways to detect the presence of a watermark: dipping the stamp in water, lighter fluid (of which Ronsonol brand seems to be a favorite), or any of the new "commercial" fluids prepared for the express purpose of detecting watermarks ("Clarity" comes to mind). Of course simply holding the stamp to a bright light source at various angles may be all that is necessary."

To read the USA Today article about the dangers of carbon tetrachloride, click here.

To learn more about watermark detection, click here.
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posted by Don Schilling at 12:01 AM