The Tunc of a glass beaker

Beaker (drinkware)

A beaker is a beverage container, and a term used in parts of the UK. A beaker is typically a non-disposable plastic or ceramic cup or mug without a handle, much like a laboratory beaker....

 is a term colloquial to the Midlands

English Midlands

The Midlands, or the English Midlands, is the traditional name for the area comprising central England that broadly corresponds to the early medieval Kingdom of Mercia. It borders Southern England, Northern England, East Anglia and Wales. Its largest city is Birmingham, and it was an important...

 of the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 that is used to describe the thick deposit of glass that forms the base of the vessel.

Etymology

There are two possible origins for the word:

The first explanation is that the word is onomatopoeic and derives from the sound that is produced when the tunc comes into contact with another surface (in many cases, a horizontal wooden bar surface). As tunk with a 'k' is defined as "a sharp blow; a thump", it has been argued that this theory does not give an adequate explanation as to why the word ends with a 'c' and not a 'k' (an unusual spelling considering that the word first appeared in common usage in the United Kingdom).

The second explanation claims that the word derives from the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 word 'tunc' which means 'then' (as in, when the tunc is reached, it is then time for another drink). However, this is a somewhat tenuous line of reasoning and relies, for the most part, on inference.

With both theories being feasible but ultimately flawed, it would be wrong to definitively accept either one of them and so the etymology of the word remains ambiguous.

It is interesting to note that there are two very similar spellings of the word that appear to be unconnected to it in this context, and are useful, therefore, only as an aside. Tunk with a 'k' is a well known card-game, also known as "Black Man's Rummy". In Turkish, the word tunç means bronze.

Purpose

Originally, the tunc was formed unintentionally as part of the glass molding

Molding (process)

Molding or moulding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a pattern....

 process. However, a well-developed tunc proved to be a useful feature of a glass drinking vessel in ensuring its structural integrity particularly in the early days of glass making.

A well-weighted tunc also provides a stable support for the drinking vessel, lowering the possibility of it being knocked over. With this is mind, it is not uncommon to find a tunc with slight flaring outwards towards the bottom of the glass.

The arguments surrounding the formation of a tunc are similar in essence to those regarding the punt of a wine bottle

Wine bottle

A wine bottle is a bottle used for holding wine, generally made of glass. Some wines are fermented in the bottle, others are bottled only after fermentation. They come in a large variety of sizes, several named for Biblical kings and other figures. The standard bottle contains 750 ml,...

, and include mechanical, historical and simply presentational theories.

Prospects

Due to advances in the production of glassware

Glassware

This list of glassware includes drinking vessels , tableware, such as dishes, and flatware used to set a table for eating a meal, general glass items such as vases, and glasses used in the catering industry whether made of glass or plastics such as polystyrene and...

, tuncs are steadily becoming less substantial. The modern tulip-style

Pint glass

A pint glass is a drinking vessel made to hold either a British pint of 20 imperial fluid ounces or an American pint of...

 pint glass often features a very modest tunc. An example of this style of glass can be found here.

As well as this, plastic imitation-glass drinking vessels are gradually becoming more popular in pubs and nightclubs where they are less likely to break and cheaper to replace when they do. Unlike traditional glass vessels, these are produced by fusing two molded

Molding (process)

Molding or moulding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a pattern....

halves together to form a complete pint glass. As such, the tunc is not produced naturally and so is less prominent than that of its glass counterpart.