12: Examining cloth
Many expensive collectibles are cloth, or are partially cloth.
This includes baseball caps worn by famous players, Civil War
uniforms displayed in museums and rare teddy bears. Some expert
collectors and examiners of valuable cloth items use black light
to help judge age and and check for restoration. An example is
a collector checking to see if the their name plate and number
are original to a jersey. An other example is collector putting
a stuffed teddy bear under black light to see if the tags and
stitching are modern.
Optical brighteners and modern cloth. As with paper,
optical brighteners have been added to much cloth made after
World War II. Used to make bright colors brighter and stain resistant,
the optical brightened clothes will fluoresce a bright white
or blue/white under black light. The optical brighteners will
typically indicate that the cloth was made after World War II.
Many 'antique' patches, hats and shirts are identified as being
modern reproductions-- or at least altered or restitched after
WII-- due to the presence of the presence of optical brighteners.
For example, collectors of WWII military patches know that many
fakes fluoresce brightly under black light.
A person who bought an antique style New York Yankees baseball
cap will be able to identify it as a modern reproduction by tags
and stitching the fluoresces brightly.
As many cloth items are made from a variety of cloths and threads,
the optical brighteners will often appear only on parts. For
example, most of a modern baseball cap might not fluoresce, but
the emblem, stitching and laundry tag might. Cloth or thread
that doesn't fluoresce brightly doesn't mean it isn't modern.
In fact, most dark cloth don't contain optical brighteners.
It is important to note that many laundry detergents have
optical brighteners, which can throw off results. If an antique
shirt was washed in the washer, it may have optical brightener
residue from the detergent. Though the granular detergent is
usually easy to identify as detergent due to the granular, dusty
Cloth tends to lose its fluorescence with time, and very gold
cloth often has no fluorescence.
Examiners and collectors identify alterations on new and old
cloth by looking for clear differences in UV fluorescence. If
a stuffed doll was patched up with a like color of cloth, the
alteration often can be identified by fluorescence difference
between the patch and the rest of the doll. This comparison and
judgment requires experience both with examining cloth, and the
dolls, jerseys or whatever is being examined.
In some cases, modern alterations are not identified by the
added cloth but the new stitching. On an antique shirt, optical
brightened thread will reveal the modern stitching. It surprising
how much the thread can stand out.
The above shows a hat in visible light
at top and a brightly UV fluorescing tag on in the inside at
bottom. Most of the hat does not fluoresce, but the tag gives
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