Dating Antique Bottles

  I am often asked "How do you know how old these bottles are?".  Here is a five minute lesson that will assist you in dating most, but not all, antique bottles.  To simplify things I will be discussing exclusively bottles that are blown into a mold which covers all embossed bottles.  There are definitely exceptions but I would say ninety five percent fall within these parameters.
  The earliest bottles will have something called a pontil mark on the base of the bottle.  There a quite a few types of pontil marks or scars but the two most common are the open pontil (O.P.) and the iron pontil (I.P.).  The open pontil will be be seen more often on smaller and lighter bottles and the iron pontil on larger and heavier bottles.  Bottles that exhibit either one of these marks will generally date between 1830 and 1860.

Open Pontil Mark

Iron Pontil Mark

The age of bottles dating after 1860 can be narrowed down by taking a close look at the lip of the bottle.  If the bottle is blown into a mold with an applied lip (bimal) the seam will not go over the lip of the bottle.  There are two ages of applied lips that one can easily detect.  Earlier applied lip bottles will have a seam that appears to go right under the applied lip.  Bottles that have this trait but no pontil mark will generally date between 1860 and the early 1880's.

Seam goes under lip in top of photo

  In contrast later bimal bottles will have a seam that just seems to fade away on the neck of the bottle.  Bottles manufactured using this process will date between the early 1880's and the early 1910's.  If you look carefully it will appear like the seam was just wiped away.

Later applied lip with seam stopping on shoulder

Not all bottles blown into a mold have an applied lip.  Some bottles and most canning jars made before 1904 are finished by grinding the lip.

Bottle with ground lip

    

The newest bottles will be machine made.  Although the automatic bottle making machine (ABM) was invented in 1904 many bottle were still being made by hand for quite a few years.  By the 1920's virtually all bottles were being made by machine.  The easiest way to identify a machine made bottle is to check to see if the seam goes over the lip.  Machine made bottles will also have a machine mark on the base but these vary by manufacturer and are more difficult to describe.

Seam over lip, machine made

Hope this helps you date that special bottle that you found in an old barn many years ago, maybe it has a pontil mark on the bottom!