Types of Bottle Molds

Bottle is one of the most commonly used containers for liquids. Its use has varied widely from simple jugs for water to intricately designed containers for fine wines and spirits. The bottle’s unique properties make it a desirable container for many different products, and its appearance has often influenced the designs of other glassware. The bottle’s unique structure, and the fact that it is non-equilibrium (non-crystalline) state, allow it to flexibly expand and contract over time. This expansion and contraction gives the bottle its distinctive shape and makes it resistant to breakage.

Glassmakers make colorless bottle glass by reducing or eliminating iron and carbonaceous impurities from the raw materials used to make it, such as sand and clay. This is done by adding decolorizing agents like selenium, manganese dioxide, or arsenic to the glass batch, and may also be accomplished with chemical processing of the molten glass during the melting phase. These processes, in combination with other glassmaking techniques, produce the various colors of glass bottles.

Full sized bottle mold – A full sized mold is one which forms the base, body, shoulder, and most of the – or in some cases all of – the neck/finish on a bottle. In contrast, a half-sized mold only forms the shoulder and part of the neck. See the full sized mold illustration on the Bottle Finishes & Closures page for an example of what is meant by this term.

Dimple – A small, molded depression in the bottle neck into which the lever wire of a toggle closure device is hooked (White 1978). The dimple is usually made with the same material as the rest of the bottle neck.

Ejection mark – A circular mark left on the base of a bottle or jar by certain press-and-blow and automatic/semi-automatic machine-made bottles (like Lynch MB Two table) that left this mark when a metal rod pushed (“ejected”) the parison out of its first parison mold to move it via the grasping ring into the second and final blow mold. This process is the basis for the “hinge mold” or “key mold” variant of the hinge bottle mold discussed on the Bottle Bases page.

Laid-on ring – Ranging from crude to refined, this was a trail of glass which was trailed around and fused into the bore or neck of a bottle. This was done to strengthen these areas and to assist in a tight closure fit – but not to prevent leaking. See the laid-on ring discussion on the Bottle Finishes & Closures pages for more information.