T he glass is narrow at the bottom but bulges out a third of the way to the top. As with the classic British “nonik” pint, the bulge makes the glass easier to stackand gives your thumb and index finger somewhere to rest. The name is spelled in fading letters near the rim and means “super tight” or “super strong” in German, which one might assume to be a reference to the drinker’s solid grip.

In fact, it hails the glass’s extraordinary durability. This is Superfest, East Germany’s “unbreakable” drinking glass. Invented in the industry-rich but resource-poor socialist German Democratic Republic, Superfest glasses were designed with the aim of making them last five times longer than ordinary drinking glasses.

They were soon found to be 10 times more durable. The company that made them went bankrupt after the fall of the Berlin Wall, but as contemporary designers are exploring more eco-friendly and sustainable production methods, the 120m Superfest glasses produced between 1980 and 1990 are more in demand than ever, fetching about €35 (£30) a pop on online marketplaces such as eBay and Etsy. Some designers even dream of bringing the technology behind them back into production.

As objects mostly made to be seen through rather than seen, drinking glasses are an oddly overlooked category of homeware design. Even when they are recognised as works of art, their value tends to be set by what goes in them. A Kurt Zalto wine glass or a Tom Dixon whisky tumbler wi.