Following a recent resurgence of cases in the state, the NSW Government is 'strongly encouraging' people to wear a mask in situations where physical distancing is not possible, such as buses, trains, shops and churches.

"Premier Berejiklian needs to make face masks mandatory on public transport, in places of worship, and in supermarkets and shopping centres - not just recommend it," Mr Barr said.

"Wearing masks will allow us to stop the spread, save lives, save jobs and keep our economy going during this difficult time."

Mr Barr agreed with the government's call that masks should be considered a "fourth line of defence" after staying home if unwell and getting tested, maintaining 1.5-metre social distancing and good hand hygiene.

"Face masks don't replace distancing or hygiene. We all must do our part and prevent the spread of COVID-19 in our community," he said.

Cessnock City Council is encouraging customers to wear face masks at its facilities including at administration building, Cessnock and Kurri Kurri libraries, the Hunter Valley Visitor Information Centre and Cessnock Performing Arts Centre.

"We all need to be taking measures to stop the spread of COVID-19. In NSW we are at a critical point and it's certainly our wish to see the Cessnock local government area COVID free," council's general manager, Lotta Jackson said.

"This is about protecting our most vulnerable residents, the elderly, those immune compromised and about safeguarding our local economy.

"We don't want to see our local businesses suffer again, like the businesses are across both Melbourne and regional Victoria."

Following these recommendations, face masks have become an in-demand item at local businesses.

Cessnock health and lifestyle store Stocked sold out of its first order within two days, and people were lined up outside the Vincent Street store on Monday morning waiting for the next batch.

"We are just trying to get ahead of it and help people," owner Chris Kroek said.

"We don't want it to be like we were with toilet paper and hand sanitiser and not be able to get them."

Wild Learning at West Cessnock is also stocking masks in its brand new pop-up shop, and sewing teacher Suzanne Schroder will include masks in her lessons on Friday and Saturday mornings from August 21.

The pop-up shop is open Wednesday and Thursday from 2pm to 3.30pm, and Friday from Friday 10.30am to 12.30pm this week. SMS Emmie on 0412 835 865 for inquiries.

Copies of mask-making guidelines are also available at Clayton Barr's office at 118 Vincent Street, Cessnock and at health.nsw.gov.au.