Freesax chaline com - Dating antique whiskey bottles
(NOTE: the article on this page is pertaining to GLASS containers, and does not apply to the subject of modern / recent PLASTIC containers, which is an entirely separate field of study, and is discussed on many other websites.
Probably in the majority of cases, single digit numbers are mold numbers, merely serving to identify a particular mold, (or section/mold cavity in an automatic bottle manufacturing machine) that was used to form the bottle or other glass item.
If a number of identical bottle molds are being used simultaneously, each mold would be assigned a number.
Date codes are often seen, especially on soda bottles from the 1930s to date, and many of these codes are embossed on the base of the bottle, placed to the right of the glassmaker’s logo. These date codes are not always obvious, or easy to distinguish from mold numbers.
It also depends on exactly which glass company produced the container, as all firms do not use the same system of markings.
Always look very closely over the entire glass bottle or other container to make sure there is not some type of logo (emblem, trademark, initials, or just a letter) that might indicate the actual glass manufacturer.