Four bases of dating
This type of embossing was engraved or "cut" into the mold at the request of the buyer ordering the specific bottle.
Many other bottle bases have what are referred to as makers marks.
When referring to "markings" or "features" on the base of a bottle on this website, we are referring to embossing, mold lines, attached glass and/or mineral deposits which are confined within or around the edge of the bottle base.
For example, the particular style of "star" on the base of the liquor bottle pictured to the left is widely acknowledged (in the collector world) to be a decorative marking of the San Francisco & Pacific Glass Works (SF&PGW - 1876-1902) since most of the bottles with this marking are either found in the West or are otherwise embossed with Western company and/or product names (Toulouse 1971; Zumwalt 1980).
For additional information, click Dating Page to go to the pertinent section of that describes the differences between these bottles.
Once you have determined which type bottle you have - or if you know already - click on one of the following links to move directly to that section of this page (there are numerous links back to this index scattered throughout the page): A.
For more information on the subject of glassmaker markings see the Makers Marks page, which is a sub-page linked to the Glassmaking & Glassmakers page.
This page is divided into two sections based on the primary methods by which bottles were manufactured - mouth-blown (hand-made) or machine-made (both semi and fully automatic) - since base features on these types of bottles generally differ significantly.
The best readily available source for classifying bottle base shapes/profiles is the "Bottle Base Profiles" illustration that was previously included in the IMACS (Intermountain Antiquities Computer System) guide.