Many people are intrigued to know how old their bottle is. There are three keys to help with dating most bottles:

1. Side seams:
   • None: bottle may be free blown, in which case it has a very uneven shape and dates before 1860. Or the bottle may have a nice even shape, but was spun in the mold to smooth out the seams; a practice common around 1900-1920.
   • BIM: side seams run from base and end below the top of lip, which is the result of Blowing In Mold (BIM). Can usually tell that lip is crude and was applied by hand.
   • 3PM: 3 piece mold. Bottom half (from base to shoulder) has no seams, then there is a seam near the shoulder that runs completely around the circumference of the bottle. From this shoulder seam are two side seams that run up the neck and end below the top of the lip. 3PM was primarily in use from 1840-70. Can usually tell that lip is crude and was applied by hand.
   • ABM: if the side seams run thru the top of the lip, then the bottle is ABM (made by an Automatic Bottle Machine). The first ABM bottles started appearing in 1905, and by 1920 most bottles were being made by this method.

2. Base type (for examples, click here):
   • Open pontilled: usually date before 1860.
   • Iron pontilled: usually date 1845-1870.
   • Smooth: usually date 1870 or later.

3. Top type (for examples, see click here):
   • Matthews gravitating stopper: date after 1864.
   • Codd stopper: date after 1873 when Hiram Codd invented this bottle.
   • Hutchinson blob top: date after 1879.
   • Lightning stopper: date after 1880.
   • Crown Top: date after 1892 (when crown top was invented).
   • Screw Top: usually date after 1920.
   • Applied lip: date before 1900.
   • Tooled lip: date after about 1890.
   • Other: there were many varieties of tops as you can see in the examples, so if the top is not crown and not screw, then rely on the other two factors (Sides Seams and Base Type) to date your bottle.

If your bottle is embossed "Federal Law Prohibits ...", then your bottle dates between 1933 (end of Prohibition) and 1970.

If your bottle is American and has a patent number, check out this Table of U.S. Patent Numbers to help date your bottle. Also see the US Patent and Trademark Office where you can do a search to find more info on a US Patent.

If your bottle is English and has a registration number, check out this Dating English Glass page that shows the year for each registration number between 1876 and 1920.

If you want further help on dating your bottle, then contact: Reggie Lynch at Email rlynch@antiquebottles.com