Tuesday, March 23, 2010

Bottle Making Mysteries

Here is an interesting website that contains some information about bottle moulds,  bottle manufacture, etc. 
Check out his posting on "mold cavity half-leaf repair marks".    We have all seen these on bottles,  there was an article on these marks in the "Antique Bottle and Glass Collector".    I have a Shriver's Oyster Ketchup  with that exact mark,   I just sold a Boley soda with similar mark.
Interesting stuff...     hat tip to Red Mathews

here's the link:

Half leaf "repair mark"~~  not so much.     Not a repair patch to the bottle.   Not a repair to the mould.  

    As reported by Warren F.,   most likely a mark or anomaly created by the pinching and then re-centering of a bottle during the early stage of bottle formation.

Another picture from Ray Klingensmith's Auction#62. 

Probably newer than the bottles we are talking about in this post.

That mould boy on the upper right looks like a bottle pincher to me.  


  1. I readily disagree with Red Mathews assertion that the unique anomaly known as a "half leaf" mark is caused by a mould repair.

    In my research of glass making and studying this unique anomaly, which happens on eastern made bottles is caused by the bottle blower. Unlike in the west, the eastern blowers were mostly using mold boys to open and close the iron bottle moulds manually. This unique mark seen in eastern glass is the result of a glass blower taking his blowpipe with a glob of metal on the end and rolling it on a marver to a cylindrical shape, then with his first breath of air into the blowpipe, expands the hot glass into a small globual. These blowers are standing on a platform a couple of feet above the floor with their blowpipe inserted in a vertical downward position, as the blowpipe is inserted in the open mould, the mould boy shuts the mould which has long handles on each half of the mould. As the blowpipe is inserted with a gather of glass slightly inflated to its natural bulbous shape; if the glass blower does not center this in the mould, as the mould is quickly shut, the outside edge of this glass is pinched. The mould is slightly opened to allow the gather free movement and centered, then shut again and the glass expanded into the mould, causing this pinched area of glass to fold over and flatten against the inside wall of the mould. That is why the outside edge is always curved (from the natural curvature of the free blown gather)and the inside edge is always straight (from the pinched glass being flattened against the inside mould wall). The whole process of blowing a bottle is barely a minute.

    In researching this particular mark, I found it to be prevalent among eastern blown glass, to include, Old Sachem & Wigwam Bitters, Wishart's Pine Tree Tar Cordial (both large and small size), Saratoga Springs Mineral Waters, Rosenbaums Bitters (large size, eastern made) etc. These marks are the result of the glass blower and mould assistant not perfecting their artistry, nothing more.

    The western moulds were mostly attached with a foot treadle apparatus and opened and shut by the glassblower who would coordinate this movement himself without the aid of a mould boy assisting.

  2. Thanks Warren,
    the foot treadle apparatus, single man operation, in western glass houses could help to explain why these "half leaf" marks do not appear on western blown bottles. At least I have never seen one on a definite western blown bottle. Seems a bit unlikely to me, that a single man operation would not "occasionally" run into the same pinching problem... as fast as they were cranking these bottles out. Your explanation is easily understood and makes complete sense.
    One thing for sure, these early bottle blowers were truly amazing in the sheer quantity of containers that they were able to produce in a days work.

  3. Right on Warren!! I agree that the lack of coordination between the glassblower and his "new" boy , is the reason for those marks.........Andy

  4. Great post, Warren. It became a topic of conversation at our bottle club meeting when the "opinion" was made in the Feb 2009 Antique Bottle & Glass Collector that this was an actual repair to the bottle. Having studied these anomalies I immediately disputed it, but had no valid explanation as to what caused it. When I read in the above link that it was a mold repair, I even further disagreed. Your explanation is the most plausible, thanks for sharing it! -- Dwayne

  5. This "half leaf" anomaly, though fairly commonly reported on many different eastern blown bottles (1850s-1860s), it has not been reported, that I have seen, on different examples of the same bottle.
    Obviously, if it was a mould repair there should be many examples showing the same repair mark.
    It would be interesting to see two or more examples of the same bottle (Wisharts, Old Sachem etc.) having the "half leaf". If they are from the exact same mould pattern, and the anomalies are in different places on the bottle... I think Warren's "pinch and re-centering" explanation should be verified.

  6. I have Western blown bottles in my collection with similar pinch marks and folds. My favorite is a GH Clarks More Reynolds

  7. There's also another Western blown Blake's residing in a Nor Cal collection with the same kind of anomaly. I also recall seeing a cobalt Owen Casy with this too.


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