MONTREAL - Canada's newly-unveiled $100 bills are expected to be the first wave of a total transformation of our currency from paper to durable polymers. But there's one drawback: the new money shrinks.

Moses Grunwald has proof. He owns a shriveled up $100 which was deformed when his friend dropped it on a baseboard heater.

Grunwald bought the currency at face value and now considers it evidence that the new currency isn't able to stand up to certain extreme conditions.

The friend's cash had fallen from his pocket onto a radiator. The new currency became wrinkled and small but the old fashioned paper bills kept their form.

"He saw that the new 100 dollar bill shrank. Nothing happened to his paper money," said Grunwald, an entrepreneur.

According to the mint, the new polymer bills cost more to make but should last two-and-a-half longer than the usual paper cash.

"I think that it's a failure for the new $100 dollar bill that it should happen with such a small amount of time," said Grunwald.

The mint tests the bills in extreme temperatures between -61 C and 100 C.

"We immersed them in boiling water and saw no change," said Martine Warren of the Bank of Canada.

And although hard to tear, she admits that the bills are vulnerable to cutting if already nicked. "If you use a blade and get a nick in these notes, the tear propagates very quickly," she said.

Those who have damaged cash should exchange it at a bank.

Canadian polymer 50 dollar bills will enter circulation this spring.

Meanwhile those fortunate enough to be packing a wad of hundreds should take care to keep their cash cool and avoid rips.