At the same time, the sale of alternatives like paper bags and paper straws had increased 150 per cent.
Like every other Foodstuffs brand, Gilmours would cease to offer single-use plastic bags at the checkout from January 1.
While some alternatives - reusable bags and paper or aluminium straws - were straight forward, the phasing out of plastic bags left some consumers at a loss as to how to clean up after pets, or deal with rubbish.
A spokeswoman for Countdown, which came under the Woolworths New Zealand umbrella, said the company had seen a boost in sales of bin liners.
"We have a range of these available to purchase in stores including compostable options," she said.
"We're also keen to share ideas about potential alternatives with our customers. For example, we recently posted a Facebook video on how to make bin liners out of newspaper."
Countdown set the ball rolling with its promise to ban single-use plastic bags by the end of the year, earlier this year.
They would, however, continue to sell plastic bin liners in store.
A spokesperson for Foodstuffs, which owned Pak'n Save, New World and Four Square stores, said sales data for bin liners was difficult to access.
"What we can say is that we urge shoppers to consider the environment when shopping for bin liners, and perhaps even use no liner at all," he said.
For those who were not keen on going sans-liner, a handful of environmentally-conscious stores had both degradable and compostable bags on offer.
Eco Bags NZ was one such company. The company, which started up 12 years ago, supplied their products to selected Foodstuffs and Woolworths supermarkets nationwide as well as smaller retailers.
Spokeswoman Clancy Simmonds said demand from supermarkets had increased over recent months - and Eco Bags now stocked a larger number of smaller retailers too.
"There are a bunch of little online places popping up now too - people wanting to become retailers of sustainable products," Simmonds said.
Meanwhile, smaller businesses were setting up shop, selling eco-friendly alternatives for individuals and smaller retailers.
Eco Straws was one such business - started by Aucklanders Rose Brownlie and Alex Sue after being inspired by a recent trip to Bali.
"We noticed that the bars, restaurants and cafes all utilised reusable straws instead of plastic," Brownlie said.
"In New Zealand we have a clean and green reputation, but we are still overfilling our landfills with plastic and not thinking about materials that can be reused."
The business, which was currently based online, sold a range of aluminium straws as well as a paper option and pipe cleaners.