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PQQLK9
06-26-2004, 03:52 AM
http://www.ibsf.org/news/images/upimages/Ivory.jpg
An Ivory ball showing early signs of cracking
http://www.ibsf.org/news/images/upimages/composite.jpg
Typical cracking in composition balls

FROM IVORY TO RESIN
filed on Friday, 25 June, 2004. 07:28 UK time
A question asking how the ivory billiard ball could be identified from its modern day counterpart was received from one of our site visitors.

Ivory

The earliest material used for billiard balls, ivory is an organic material and therefore has distinctive features absent in the artificial balls. When still attached to an elephant, ivory puts on a layer of growth each year, and the result is that it displays a very
distinct "grain" much the same as wood, which is clearly visible on the finished ball.

Additionally, all tusks would have a central nerve which ran from one end to the other. Depending on which part of the tusk the ball was cut, this mark will be clearly visible to a greater of lesser extent at the "poles" of the finished ball. Sometimes, these would be drilled and plugged with ebony and supplied as a "spot" ball for billiards or pool.



Ivory, in exactly the same way as wood, will absorb moisture through the "end grain" much more readily than it will through the surface. When these balls are dyed they will therefore have a greater penetration of dye at the "poles" than they will at the "equator". After a very short time in play this results in a paler band of colour
appearing around the circumference in this area. Sometimes the colour is worn away completely in this area, while remaining quite solid at the top and bottom of the ball. This is a very distinctive characteristic of ivory which you can see at ten paces !

The moisture absorption properties also have another effect on ivory. It will cause the ball to expand and contract in an uneven way when exposed to humidity. This eventually causes flaky cracks to appear at the surface around the poles. Most ivory balls you will find these days are at least 70 years old and almost all of them will display this type of cracking to some extent. They look like short, fine, black lines, running around the circumference.

Lastly, ivory balls, even the oldest examples, can be polished with very little effort to produce a high gloss finish which is as smooth as glass.

Composition

The commonest type of composition balls are essentially made from powdered animal bone bound together with plastic "glue" (Cellulose Nitrate). They started to become popular in the 1890s and had superseded ivory almost completely by the early 1930s.



They are distinctive because they have a uniform colour, and even when new, could not hold a shine very well. They have not been made in England since the early 1970's so the examples you will see nowadays are invariably very dull in appearance.

Additionally, you will see on many examples, a very fine and uniform cracking all over the surface of the ball. This is caused by the constituent parts expanding and contracting at different rates due to temperature variations.

Phenolic Resin

These balls were popular in mainland Europe and America in the 1930s and eventually took over from compositions to become the "modern" ball used in the game today.

They are usually quite brightly coloured, more so than the compositions which would be almost a pastel shade by comparison. Older balls tend to have "creamy" whites and very deep reds, with the colours becoming lighter and more vibrant the more modern they are.

Phenolic Resin is a single material, not affected by normal temperature fluctuations, so there is never any cracking and will hold a shine almost as well as ivory.

Article and Photographs courtesy of Peter Ainsworth
http://www.ibsf.org/news/newsline.php?subaction=showfull&id=1088144920&arch ive=&cnshow=headlines&start_from=&ucat=10&

SPetty
06-27-2004, 12:02 PM
I don't know, PQQLK9, this looks pool-related to me!

Nice article. Thanks.