Britain’s New Bank Notes: Secure. Durable. Not for Vegetarians.

After studying alternatives, the Bank of England said its new polymer bills would continue to have a trace amount of animal products.

LONDON — Britain’s new bank notes are harder to forge than their predecessors. They are also more durable, able to survive a washing machine cycle. They can even be dipped in curry with no adverse effects.

None of that is much consolation to vegetarians, however — the notes are printed on polymer, which uses tallow, a hard, fatty substance usually made from rendered meat, rather than on the cotton-based paper that was used before.

On Thursday, the Bank of England, which prints bills circulated in England and Wales, said that it would continue to use the polymer for the 5-pound note, worth about $6.50, introduced last year, as well as the £10 bill that debuts in September and the £20 note that will enter circulation by 2020.

“This decision reflects multiple considerations including the concerns raised by the public, the availability of environmentally sustainable alternatives, positions of our central bank peers, value for money, as well as the widespread use of animal-derived additives in everyday products, including alternative payment methods,” the Bank of England said in a news release.

The bank said it had not taken the decision lightly.

It said it had chosen the polymer notes for their durability and for their ability to incorporate new security features, adding that they were better for the environment than the traditional cotton-based paper notes. After the polymer notes’ debut last year, the Bank of England’s governor, Mark Carney, dipped one of them in a curry to demonstrate their durability.

The bank apparently did not anticipate the pushback on the use of a trace amount of animal products — typically less than 0.05 percent — in the notes.

An online petition to stop the use of tallow garnered more than 135,000 signatures.

The Bank of England explored alternatives in a monthslong consultation. About 3,500 people responded to the bank’s request for opinions on the use of animal products in its notes. Of those who expressed a preference, 88 percent were against the use of animal-derived additives, while 48 percent were against the use of additives derived from palm oil, which the bank had explored as a possible alternative to the tallow.

Despite the overwhelmingly negative response to the use of tallow, the Bank of England said it had to balance those concerns against its “other public duties and priorities.”

In part, the cost of switching would have been significant: about £16.5 million over the course of the next decade, the bank said.

The Bank of Scotland, one of three banks that prints the new polymer bills in Scotland, posted on Twitter in November that its notes were vegan-friendly after receiving assurances from its manufacturer that the notes were free of animal products.

But the manufacturer later said that trace amounts of animal products were also found in the notes printed by the three banks.