Define the bases dating
Markings or features on the base of a bottle are usually formed either by the mold or by a pontil rod (or punte)..both.On machine-made bottles additional markings can be the product of the automated machinery which produce the bottle, but which are not part of the mold itself.(British Glass 2004) In conjunction with the finish (lip), the various attributes and features found on the base of a bottle allows for some of the better opportunities for the manufacturing based dating of a bottle.This potential for datable features is very useful since bottles are more often than not lacking embossing - an attribute which can often enhance dating opportunities.This page is divided into two sections based on the primary methods by which bottles were manufactured - mouth-blown (hand-made) or machine-made (both semi and fully automatic) - since base features on these types of bottles generally differ significantly.There is also large section on pontil marks or scars due to its size (hyperlink found several places below).447,000 L PROJECTED / YEAR -- R4H becomes incorporated and a partnership with M S Swaminathan Research Foundation is officially established, enabling the construction of 12 tanks in the village of Edayazham.
The bottom of a bottle is usually the thickest part, retaining more temperature throughout the production line.
Click Owens-Illinois bottle base to view a picture of the relatively elaborate bottle base mold markings used by the Owens-Illinois Glass Company during the mid-20th century.
Some markings indicate the glassmaker or manufacturer which produced the bottle; other markings were mold identification numbers or of unknown glass maker utility.
To a lesser degree, the base can sometimes provide other information about a bottle like its intended function.
When referring to "markings" or "features" on the base of a bottle on this website, we are referring to embossing, mold lines, attached glass and/or mineral deposits which are confined within or around the edge of the bottle base.
Also, shape is extremely variable and usually only loosely connected with age and function.