How to identify the age of glass bottles?

glass bottles

Since its invention in 1AD by the Romans, glass bottles have been used for various purposes for centuries. Like coins and frames, they have been one of the most collectable antiques. 

The older the glass bottle, then the higher the price tag it bears. And, the modernizing generation is demanding more intriguing shapes, vintage colored and classic pieces of glassware to preserve in their collections, for they have those antique classy charm and quirks, which the advanced technology glassware don’t have. 

The question as to “how to tell the age of a glass bottle” often arises when you are at a museum, an antique shop, or an ancient home. There are several marks and hidden symbolic meanings which tell us about the era of its creation. 

When you get the information regarding the production techniques and strategic markings, you can browse through your estate sales and make the correct decision. By taking note of a few patterns and appropriate guidelines discussed below, one can easily estimate the approximate age of antique glass bottles. 

glass bottles

Blowing-glass Technique

In the mid 19th century towards the end of the 20th century, the majority of glass bottles used to be shaped by the glass blowers themselves. In the mid 20th century the glass bottle production industry was taken over by automation. 

During the 1800s skilled glassblowers carefully blew molten glass into iron or wooden molds. When the hot compound cooled, the artisans would give final touches and craft of the lip. It was an intensive craft in the 1800 and it is fancy for bottle diggers to have one from this production in their collection.

Automated Machinery 

In the year 1892 semi-automatic bottles making machines were invented which transformed the game. The automatic bottle machine molds the bottle mouth and then the body with no need for hand finish any longer. However, they are less appealing due to machinery operation and considered inferior to handblown oldies. 

The Scarred Base

glass bottles

The base of a glass bottle has a significant notation of its age. Before the middle of the 19th century, there used to be pontil marks as the signature of glass bottles. 

*Pontil is an iron rod that was used to hold the bottle from the base during the process of manufacture. 

This role used to leave a ring-shaped open scar at the base of the bottle which is called the pontil mark, depicting that the bottle was mouth-blown. In the period after the 19th century and the early 20th century, the old mouth-blown techniques became obsolete and the manufacturing process became automatic. This clearly suggests that the bottle was created during the early 19th century or before. 


The last 150 years era had glass bottles manufactured by blowing molten glass into molds made up of wood or iron. The phase when the bottles were separated from the mold, used to leave a slightly visible seam, from the base of the bottle to the mouth or the shoulder. It can be said that the higher the seam, the newer the bottle. 

Suppose a glass bottle with up to the curvy shoulder of a glass bottle can be of any year before 1860 while the one with seams scar to the topmost position belongs to the period nearer to 1900. Glass bottles of recent origin are produced with sophisticated technologies and do not possess seams. 

Shaped Mouth

During the early 18th century the mouth of glass bottles used to be extremely rough. At the initial advent of the 19th century, they were transformed into crude tapered lips. Then, by the middle, the mouths began to be created with a refined and distinct shape. 

Double rounded lip-shaped bottles were gaining market popularity at the same time. The second half of the 19th century witnessed the evolution of preference into thick blog top structures of bottle mouths. These commonly used vessels were then transitioned into doughnut shapes in the late 19th century. 

Shaped Top

The top of glass bottles poses a variety of shapes and types. These include Crown top, screw top, cork top, which were the most famous categories prevailing. 

  • Cork-top glass bottles: costs have been dominantly used to cover the mouse of glass bottles in the industry. They were more prevalent in manufacturing companies existing in the 18th century. 
  • Screw-top glass bottles: these were invented during the beginning of the 1800s era. These however could not become market popular while machine-made bottles started to emerge during the mid-1900s. 
  • Crown-top glass bottles: they came into the market and ruled highly during the late 1880s, the Victorian age. Until the 1900s when advanced machine-manufactured glass bottles took over the market this was extremely popular. 

Embossed Markings

Letters or markings carved on the side or at the base of glass bottles can depict the age and origin of the bottle. They may be in the form of signs, symbols, numbers, words, or letters that were hard to properly carve out in the past. 

The intensity and sharpness can indicate a certain age based on whether the markings are half-etched or deformed. This embossing technique provides a straightforward way of telling the age of glass bottles when the emboss contains the name and date of manufacture. 

Example- CB denotes Clevenger Brothers, glassblowers from New Jersey.

Colour History

glass bottles

The color of a bottle signifies its value and age. Bottles of rare colors like yellow, teal, and amethyst, etc., are considered valuable while bottles of colors like clear, amber, and black possess lesser value. Knowledge regarding the history of colored glasses can give off the estimate of the period of manufacture of the desired bottle if belonging to this era. 

Like, amber color glass bottles were introduced in the 19th century, Aqua-glass used between the 1850s-1880, Amethyst between early1840- early 1880s, and hence, the bottles at hand would be of that time and not before, while transparent bottles introduced in 1662, could only belong to the years after.  


Glass bottles are beautiful pieces of antiques. They embed some history of the era within and are valuable assets to vintage collectors. If you are one of them or you are just starting, you must have some knowledge regarding the determination and authenticity of your elements. 

Due to demand, there are many reproduced or dated vintage and costly glass bottles out there which sometimes makes it difficult to differentiate between a real and a fake piece. Good research and first-hand experience should be practised to create and maintain an aesthetic collection, without being scammed or confused. 

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