How do you date old bottles?

In most cases, one- or two-digit numbers are actually mold numbers that indicate the specific bottle mold or section in an automatic bottle machine. If numerous molds were identical, each one received its own number. Base numbers also indicate bottle styles or shapes, manufacturing dates, or factory location codes.

Do old bottles have seams?

YES - The bottle has embossing or visible vertical side mold seams somewhere on the body between the heel and the base of the finish or lip. A bottle may have mold seams but no embossing, but all embossed bottles were molded in some way and have mold seams even if they are not readily apparent.

How can you tell if a bottle is valuable?

While not all old bottles are valuable, an older bottle is more likely to be worth more than a newer one. Seams and pontil marks are two of the ways you can determine a bottles age. The pontil mark is the mark at the bottom of the bottle where it was attached to the glass blowers pontil rod.

What do numbers on bottom of glass bottles mean?

mold identification Many bottles carry only a number (or numbers) on the base. These marks often served as some type of mold identification, indicating a particular mold used by a glass factory. If a number of identical molds were produced for making a certain type of bottle, they would often be serially numbered (such as 1 to 12).

Does hand blown glass have seams?

Blown glass is an ancient form of glass making that is still used in the fine arts. The resulting glass item will often have a blown look and glass varying in thickness. It will not have a seam. It often has a pontil mark, where the pipe was attached.

How can you tell if something is blown glass?

A small pinched area around the lip of a vase indicates the spot where blown glass is removed from the blowing tube. Finding a pinched area at the lip or opening of the vase is a good indicator of blown glass. Instead of a pinched area, you may find what appears to be a scar or a swirl on the bottom of the base.