Antique Tips: Date Hand Blown Glass

This articles discusses the how to date antique hand blown glass with basic instructions and tips.

Many people collect antique hand blown glass, such as drinking glasses and bottles. Most pieces date to the 18th and 19th centuries, as earlier glassware is difficult to find and somewhat rare. In order to determine the age of hand blown glass one needs to understand the history and technique of glass making, as well as shape, style, and decoration.

The process of hand blowing glass is thought to have originated in the first century BC. It is attributed to the Romans, who blew a molten substance into molds and then shaped it into vessels. Centuries later, the Babylonians developed the technique of using a long metal tube to blow molten substances used in glass-making and create bottles or drinking glasses.

Essentially these two glass-making techniques remained the same until the invention of the press-molding machine in the 1820s. With the development of this technology, the molten substances used to make glass could be pressed into a mold instead of being hand blown. The new technology enabled the production of a variety of glass tablewares such as pitchers, decanters, glasses, plates, and bowls. Eventually pressed glass replaced hand blown glass, although hand blown glass is still being made today by contemporary artisans.


Collectors are able to determine the age of bottles by looking at several features. Early bottles were either hand blown or blown into a mold. Bottles that were made between the late 17th century and the mid 19th century have a pontil mark. The pontil mark is a circular depression on the bottom of the bottle. It is made when the pontil rod is transferred from the blowpipe for final shaping and finishing. After 1800, the pontil was usually ground down and polished so it was not as noticeable, but it was still visible.

The shape of the lip and the way it is attached to the bottle is also an important feature in dating bottles. For example, a flared lip dates from the second quarter of the nineteenth century, while an applied round band is from a slightly later period. The earlier the bottle, the more crudely the lip is applied.

Drinking Glasses

Features such as the shape of the bowl (the part one drinks from), the stem, and the foot of the glass are used to determine the age of drinking glasses.

The funnel shape is the earliest type of bowl and dates from the turn of 18th century, followed by ovoid, bell, and round shaped bowls, the latter dating from the mid 19th to the present.

The stem is probably the most important feature when dating drinking glasses. During the mid 1700s, stems are plain and hollow or molded pedestal styles. Twists such as air and opaque begin to appear in the middle of the 18th century, while faceted stems indicate the turn of 19th century.

The foot is where the pontil mark is located. As with bottles, a pontil mark (ground and polished after 1800) is present from the late 18th to the mid 19th century. The shape of the foot also can help determine age. For example a square foot indicates the glass dates to circa 1800.


The features most important in determining the age of a decanter are the shape of the bottle and the style of the stopper. Cruciform shapes are one of the earliest shapes and date to the second quarter of 18th century. Bell shapes were popular in the late 18th century, and onion-shaped decanters were made beginning in the mid 18th century.

A spire type stopper usually dates from the mid to late 18th century, followed by bull's eye and then mushroom-style stoppers both dating to the late 18th century and early 19th century.

When used in conjunction with other identifying features, such as age and wear marks, the age of a drinking glass can be determined by understanding what the glass was used for. For example a rummer glass, which was used to drink grog in the late 18th century and is a specific shape, with a wide bowl and short stem.

Collecting and dating antique hand blown glass is an enjoyable hobby. As with most antiques, there are many reproductions made. The best way to become familiar with period hand blown antique glassware is to visit historic houses, museums, and reputable dealers in antique glass.

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