Wine bottle sizes have a rather fascinating story and history that goes along with the wine itself. One rather intriguing aspect of these wine bottles is called a punt. There really is no common explanation or even agreement why the punt exists but there are several theories.
Wine bottles at one point in history were free blown by using a blowpipe and something called a pontil. Creating wine bottle sizes in this fashion leaves what is called a punt mark at the bottom of the bottle. Bottle makes indented this mark so it would not scratch tables or simply tip over.
Another theory was that this style of wine bottle was used by the servants of wealthy men. Often times, the servants were very aware of what was going on in their village or town and became valuable tools to their masters. Legend has it that the code was developed that a servant would put their thumb in or out of the punt to deliver a surreptitious message about the guest to his master.
Of course there were many more common and useful tributes to the punt in various wine bottle sizes. It would act as a place where someone who was pouring it could put their thumb for stability and spills were much less likely to happen. This actually increases the strength of the bottle thus making it easy to accommodate the high pressure of champagne and sparkling wines. The punt is also attributed to decreasing the shatter rate of the various wine bottle sizes by significantly reducing the resonance factor of the bottle. From an aesthetic point, the punt actually acts like a conduit for refracting light in such a way that it enhances the color and beauty of the wine. Also, the punt makes the various wine bottle sizes heavier and thus presents more volume to a buyer without actually having anymore liquid thus tricking the consumer while making the seller happy.