Dating vintage bottles
Check for lack of bubbles and uniform glass thickness.
This is another indication of a machine-made bottle. Most bottles with embossed lettering date from the late 19th century and later. Keep in mind that older technology often persisted and some bottles date later than you might think.
Is a pontil mark present along with disappearing side mold seams? Do the mold seams disappear in the neck, but the bottle lacks a pontil mark?
Blown-in-mold bottles without pontil marks date circa 1860s to 1910s.
Some technological changes were expensive and not adopted by glass makers until it became an "adapt or perish" issue and many glass factories just perished.
The shift to the fully automated bottle machine from mouth-blown and some semi-automatic methods in the early 20th century is the classic example (Toulouse 1967, 1969a). The same bottle could have been recycled and reused many times for many years before finally being discarded - entire or broken (Busch 1987).
Dating antique bottles requires knowledge of the evolution of bottle technology and the ability to research manufacturers and bottling companies.
Please be aware that in order to gain the maximum information about any particular bottle (e.g., dating, typing) the user must usually must review a number of pages within this website.
This technology lag makes some diagnostic characteristics better than others for dating. As a corollary to #1, consider the following quote: "Treat terminal dates with care.
We can always have some indication of a starting date for a technique if we can find who first put the idea into practice.
Additional reference materials outside of this website must often be consulted to narrow down the date of any item as far as is possible and to really get a "feel" for the history of the bottle in question.
The information on this website will, however, usually produce a reliable manufacturing date range for a majority of American utilitarian bottles manufactured from the early 1800s to the mid-20th century.