Coca-Cola is to test a paper bottle as part of a longer-term bid to eliminate plastic from its packaging entirely.
The prototype is made by a Danish company from an extra-strong paper shell that still contains a thin plastic liner.
But the goal is to create a 100% recyclable, plastic-free bottle capable of preventing gas escaping from carbonated drinks.
The barrier must also ensure no fibres flake off into the liquid.
That would pose a risk of altering the taste of the drink – or potentially fall foul of health and safety checks.