Antique Glass Bottle Identification Guide: Dating & Valuing Your Historic Finds

Examining Mold Seams

Mold seams are perhaps the most reliable indicators of a bottle’s age. These vertical lines appear where separate parts of the mold came together during the bottle’s creation. The height and appearance of these seams can tell you a lot about when the bottle was made:

Bottles made before 1860 typically show no mold seams or very faint ones that extend only partway up the bottle, as the neck and lip were hand-finished.

Seams that rise to the shoulder but disappear before reaching the neck, indicating a three-piece mold was used but the top was still hand-finished.

Seams that extend higher on the neck but still don't reach the lip, showing a transitional manufacturing process.

Seams that reach all the way to the top of the lip, but are often thicker and more prominent than later machine-made bottles.

Seams run completely from bottom to top of the lip, becoming progressively thinner and less noticeable over time.

Pontil Marks and Bottle Bases

The base of a bottle contains valuable information about its age and method of manufacture:

As the Society for Historical Archaeology notes, “Some markings indicate the glassmaker or manufacturer which produced the bottle; other markings were mold identification numbers or of unknown glass maker utility.” These marks can be crucial for identification and dating.

Bottle Mouth/Lip Styles

The finish or lip of a bottle underwent significant changes as production methods evolved:

Glass Color as an Age Indicator

The color of glass can provide additional clues about a bottle’s age. While not definitive on its own, when combined with other features, glass color helps narrow down the time period:

• Aqua/Light Blue-Green: Common in bottles from the 1800s through early 1900s; this was the natural color of glass without additives
• Black Glass (appears very dark olive): Popular for liquor and wine bottles from the 1750s-1880s
• Amethyst/Purple: Clear glass containing manganese dioxide that has been sun-exposed; typically dates from 1880-1916
• Cobalt Blue: While used in various periods, was particularly popular for medicine and poison bottles in the 1890s-1930s
• Amber/Brown: Common throughout bottle history but became standardized for beer after 1910
• Milk Glass: Popular for cosmetic and ointment containers from the 1870s-1920s
• Colorless (Clear): Became increasingly common after 1880 when better decolorizing agents were developed

Common Bottle Shapes and Their Functions

The Society for Historical Archaeology’s Bottle Typing/Shapes page explains: “The shape of an historic bottle is usually indicative of what the bottle was most likely used for, i.e., what it contained. What a bottle was used for is directly connected to the commercial intent of the manufacturer or creator of the product.”

Specialized Features for Specific Uses

Some bottles have distinctive features that immediately identify their purpose:

• Hutchinson stopper indentations: Found on soda bottles from 1879-1912
• Wide-mouth with glass lid groove: Commonly used for food preservation jars
• Narrow-necked with ring finishes: Designed for cork stoppers in wine or liquor bottles
• Small, flat bottles with dauber/applicator neck: Typically shoe polish or cosmetics
• Embossed skull and crossbones or irregular shapes: Poison bottles intended to be identifiable by touch

According to Antique Trader, “Regarding bottles, the trademark usually appears on the bottom of the bottle, possibly on the label, and sometimes embossed on the face or shoulder.”

Types of Markings Found on Bottles

• Manufacturer Marks: Symbols or initials of the glass company that made the bottle
• Product Marks: Name or brand of the product contained within the bottle
• Place Names: City, state, or country where produced
• Patent/Registration Marks: Patent dates or registration numbers
• Capacity Markings: Volume indicators like “quart” or “pint”
• Mold Numbers: Numbers used to track which mold created which bottle

Common Glass Manufacturer Marks

The GLASS BOTTLE MARKS website notes: “A few examples of ‘glass bottle marks’ on utilitarian containers would be ‘I inside a diamond’, ‘B in a circle’, ‘R & CO’, and ‘N inside a square’.”

Some common and collectible maker’s marks include:

Reading Date Codes

Many manufacturers included date information within their marks:

• Owens-Illinois: After 1929, used a number to the right of the maker’s mark to indicate the year
• Anchor Hocking: Number to right of anchor symbol indicates plant; number to left indicates year
• Hazel-Atlas: Date code often appears as a number below the H-A logo

Patent Dates

Patent dates on bottles can sometimes be mistaken for manufacture dates. As the Historic Bottle Website warns: “A patent date on a bottle is NOT the date the bottle was made but instead is the date that particular feature, finish, or design element was patented.” The bottle may have been manufactured for many years after the patent date.

Condition Factors That Affect Value

Value Factors Beyond Condition

While condition is paramount, other factors significantly influence a bottle’s value:

• Rarity: Limited production runs or bottles from short-lived companies
• Age: Generally, pre-1900 bottles command higher prices
• Aesthetic Appeal: Unusual colors, elaborate embossing, or distinctive shapes
• Historical Significance: Association with notable events, places, or people
• Regional Interest: Local collectors often seek bottles from their area
• Color Rarity: Uncommon colors like cobalt blue, true red, or yellow
• Completeness: Original labels, stoppers, or packaging increase value

Current Market Value Ranges

While individual bottle values vary widely, these general price ranges can provide guidance:

In a recent forum post on Antique Bottles, Glass, Jars Online, a collector noted about a Bromo Seltzer bottle: “It was a powdered drug that was sold by the Emerson Drug Co. Hard to put an exact date based on the pictures you have shown, but I would say early 1900’s to 1920’s. The value is about $5-10.”

Online Resources for Bottle Identification

The online bottle collecting community has created a wealth of detailed resources. According to a recent Reddit post in r/BottleDigging: “This is a fantastic resource for identifying age of old bottles. I have used it extensively.”

Comprehensive academic resource covering all aspects of bottle identification and dating with detailed photographs and examples.

Extensive database of manufacturer marks found on glass bottles and jars, organized alphabetically with historical information.

Active community forum where collectors share information and help identify mystery bottles.

Detailed guide to glassmaker marks found on bottle bases and bodies, with dates and company information.

Well-illustrated guide to determining bottle age using physical characteristics.

Active subreddit where enthusiasts share finds, ask for identifications, and discuss bottle collecting and hunting.

Printed Reference Materials

Despite the wealth of online information, many bottle collectors still rely on printed reference books for in-depth information:

• “Antique Trader Bottles Identification & Price Guide” by Michael Polak
• “Digger Odell’s Bottle Price Guides” by Digger Odell
• “Collecting Applied Color Label Soda Bottles” by Tom Haunton
• “The Illustrated Guide to Collecting Bottles” by Cecil Munsey
• “Bottle Makers and Their Marks” by Julian Harrison Toulouse

Bottle Collecting Clubs and Organizations

Joining a bottle collecting club provides access to expert knowledge and networking opportunities:

• Federation of Historical Bottle Collectors (FOHBC)
• Antique Bottle Collectors Association
• Regional bottle collecting clubs (most major cities have them)

Mobile Apps

Based on related searches for “old bottle identification app” and “bottle identifier app,” these digital tools are increasingly popular:

• Bottle Identification Apps: Several apps allow you to photograph a bottle and receive possible identifications
• Antique Price Guide Apps: Databases of sold items with photos for comparison
• Collector Community Apps: Platforms where collectors can share images and get feedback

Online Databases

Some museums and collecting organizations maintain searchable online databases:

• Museum Collection Databases: Many historical museums with bottle collections allow online browsing
• Virtual Bottle Museums: Digital collections showcasing examples by type, maker, and era
• Auction Archives: Past auction results with photos and descriptions

While technology continues to advance, experienced collectors note that nothing replaces hands-on knowledge gained through examining many bottles over time.

To identify an old glass bottle, examine these key features:

1. Mold seams: The height and appearance of seams indicate manufacturing method and age
2. Base markings: Look for pontil marks, manufacturer symbols, or numbers
3. Lip/finish style: Applied, tooled, ground, or machine-made finishes correspond to different eras
4. Glass color: Certain colors were common in specific time periods
5. Embossing: Manufacturer marks, product names, and patent dates offer direct evidence
6. Shape: Bottle forms often indicate their original purpose

For most accurate identification, combine multiple indicators rather than relying on just one feature.

The most reliable way to determine a bottle's age is by examining the mold seams. As the Society for Historical Archaeology states: "It is true that the mold seams can be used like a thermometer to determine the approximate age of a bottle. The closer to the top of the bottle the seams extend, the more recent was the production of the bottle."

Pre-1860 bottles typically have faint seams that don't reach the neck.
Bottles from 1860-1880 have seams that reach the shoulder.
Bottles from 1880-1910 have seams extending up the neck but not to the lip.
After 1910, machine-made bottles have seams that run all the way to the top of the lip.

Other dating clues include pontil marks (pre-1860s), glass color, finishing techniques, and manufacturer marks.

Markings on bottle bases can include:

1. Manufacturer marks (logos, initials, or symbols of the glass company)
2. Mold numbers (used to track production)
3. Date codes (often a one or two-digit year number)
4. Plant codes (indicating which factory produced the bottle)
5. Pontil marks (rough circular scars on very old bottles)
6. Valve marks (circular marks with radiating lines seen on bottles from 1900-1940s)

As noted by the Society for Historical Archaeology: "Some markings indicate the glassmaker or manufacturer which produced the bottle; other markings were mold identification numbers or of unknown glass maker utility."

To date a bottle, examine these features in combination:

1. Mold seams: Their height and prominence indicate manufacturing era
2. Pontil marks: Present on bottles made before approximately 1860
3. Manufacturing marks: Many companies included date codes in their maker's marks
4. Glass color: Certain colors were popular during specific periods
5. Finish type: The bottle's mouth/lip style evolved over time
6. Embossing style: The appearance and content of embossed text changed through different eras

According to bottle dating experts: "Most bottle manufacturers molded the year into the glass at the bottom of the bottle in 2-digit format. You'll often find it in the lower right portion when looking at the bottom (some dates are much easier to distinguish than others)."

Remember that patent dates on bottles indicate when a design was patented, not necessarily when the bottle was manufactured.

Yes, old bottles can have significant value, but it varies dramatically based on:

1. Age: Generally, pre-1900 bottles are more valuable than later examples
2. Rarity: Limited production runs or bottles from short-lived companies command premiums
3. Condition: Mint condition bottles without chips, cracks, or staining are worth more
4. Color: Unusual colors like cobalt blue, true red, or yellow significantly increase value
5. Historical significance: Bottles associated with notable events or places
6. Embossing quality: Clear, detailed embossing is preferred
7. Closures: Original stoppers or closures add value

Common machine-made bottles from the 1920s-1950s typically sell for $5-25, while rare pontiled bottles from before 1870 can command hundreds or even thousands of dollars. Extremely rare figural bottles or those in unusual colors might fetch $5,000 or more at specialized auctions.

Yes, there are several apps designed to help identify antique bottles, though they should be used as supplementary tools rather than definitive sources:

1. General object identification apps that use AI to recognize items in photos
2. Specialized antique identification apps that connect to databases of collectibles
3. Auction house apps that provide access to past sales records

Based on related search data, many collectors search for "old bottle identification app" and "bottle identifier app" for both iOS and Android devices. However, most experienced collectors caution that these apps have limitations and should be used alongside traditional research methods like reference books and expert consultation.

For the most accurate identification, nothing replaces the knowledge gained through examining many bottles and consulting established resources like the Society for Historical Archaeology's bottle identification website.

The skills developed through bottle identification—attention to detail, research proficiency, and knowledge of historical manufacturing—can be applied to many other collectibles. As you become more experienced, you’ll find yourself spotting subtle clues that might elude novice collectors.

Remember that bottle identification often involves multiple factors rather than a single definitive feature. The combination of manufacturing characteristics, maker’s marks, design elements, and physical properties provides the most accurate picture of a bottle’s origin and age.

Whether your interest lies in building a valuable collection or simply appreciating the craftsmanship and history embodied in these glass artifacts, the journey of identification is both intellectually stimulating and rewarding. Each bottle tells a story—about its maker, its contents, and the people who used it—waiting to be discovered by those who know how to read the signs.

Comprehensive academic resource with detailed information on bottle identification, dating methods, and typology.

Extensive database of glass bottle manufacturer marks with historical background information.

Detailed guidelines on using physical characteristics to determine bottle age.

Active community forum where collectors help identify mystery bottles and discuss collecting.

Illustrated guide to determining bottle age through physical characteristics.

Subreddit dedicated to bottle collecting, digging, and identification with an active community.

Guide to determining glass bottle age through examination of physical characteristics.

Information on how to identify bottles using trademarks and maker's marks.