Paper or plastic? No, not what kind of bag do you want; it’s what kind of money you’ll use to pay, at least in Britain.

The Bank of England announced Wednesday that, beginning in 2016, it will start issuing polymer banknotes — in other words, plastic money — in place of the paper kind. New five-pound bills put into circulation that year will not only feature a portrait of Winston Churchill but should be more resistant against wear and tear and unintended journeys through the washing machine.

The switch to plastic is expected to save money, in more ways than one. The polymer banknotes should last at least 2 1/2 times longer than paper ones, officials say. And that means printing costs will be less in the long run.

“Ensuring trust and confidence in money is at the heart of what central banks do,” Mark Carney, the governor of the Bank of England, said in a statement. “Polymer notes are the next step in the evolution of banknote design to meet that objective. The quality of polymer notes is higher, they are more secure from counterfeiting and they can be produced at lower cost to the taxpayer and the environment.”

But this is a country that loves tradition and can be suspicious of slick innovations. Britain also jealously guards its currency. It has clung tenaciously to the pound when other European nations have opted for the euro.

Christopher Jeffery, editor of Central Banking Publications, a trade magazine based in London, said that there seemed to be no stopping the move to polymer.

“Pending some kind of catastrophe, it’s going to be more of a continued trend toward using polymer,” Jeffery said.

The United States remains a notable holdout. Officials at the Bureau of Engraving and Printing have said that they have looked into switching to plastic, but a spokeswoman said there were no current discussions.

Before deciding to tinker with the banknotes, the central bank went on a listening tour in the fall, going across the country patiently explaining the benefits of plastic bills and collecting feedback. Bank officials said that nearly 13,000 people responded: 87 percent approved of polymer notes, 6 percent disapproved and 7 percent were neutral.

One skeptical man told the BBC that the prototype felt “a bit like Monopoly money.”

Plastic fivers will roll off the bank’s presses in eastern England in 2016, with 10-pound notes, featuring a likeness of author Jane Austen, to follow a year later. Both will be slightly smaller than their paper counterparts. As a reassuring constant, Queen Elizabeth II’s portrait (or her successor on the throne, if she has died) will continue to grace all British currency.

Britain is not the first country to make “paying with plastic” a phrase as applicable to cash as to credit cards. Any American who has traveled north of the border knows that Canada’s notes are all polymer-based. (Coincidentally or not, Carney was governor of the Bank of Canada before taking up his current post in London earlier this year.) Australia, another former British colony, also uses plastic money.

Officials say the new notes will be hardy enough to come through a washing machine unscathed. But, they warn, ironing will cause them to melt.

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Richard Wall, the director of currency at the Bank of Canada, dismissed claims that polymer bills melt after being left inside cars on hot summer days or become brittle and snap in extreme cold. He said that temperatures that would melt the bills would also melt interior plastics in a car. Tests show that polymer bills can withstand temperatures as high as 284 degrees Fahrenheit and as low as minus 103.

In an unscientific test using a household oven set to 280 degrees Fahrenheit, a new Canadian 5 dollar note did not melt. But after eight minutes, it started to smell bad, shrink substantially and curl markedly. Its translucent security features also became opaque blobs.

Wall also refuted a widely held belief in Canada that the new money was infused with a maple syrup scent.