Women who sew the traditional "meri blouse", a type of dress introduced by missionaries, fear their industry is being undermined by cheap Asian imports.
They want rules to ensure cultural items can only be made in Papua New Guinea so they can keep earning an income.
Regina Robert sews meri blouses and sells them at Port Moresby's handicraft market.
"Those of us who worked in the market before used to make good money because there was not much competition," she said.
"Now there's lots of competition from other provinces and China — and this is why we don't make good money."
The meri blouse is normally worn to church, but the garment is also very popular for special occasions.
Ms Robert is proud of the ones she makes in the colours of PNG's national flag.
"We stitch it in black, white, yellow — and we print the bird of PNG and the star on it so that people will like it," she said.
The streets of PNG's towns and cities fill with vendors selling PNG-themed clothes in the lead-up to the country's Independence Day on September 16.
It provides valuable income for vendors like Dulsie Mathias, who profit from the patriotic fervour in the lead-up to the national day.
"We got Independence in 1975 and now PNG is a free country and we are coming to sell things about our day in September," she said.
The products Ms Mathias is selling are made in China, and her meri blouses are significantly cheaper than those made by the local cottage industry.
Seamstress Dulcie Maliaki sews the garments at her family home in the suburbs of Port Moresby.
"We have all sorts of shapes and forms, PNG women, so I think the meri blouse covers and makes us look good," she said.
"I have a lot of customers who come — young women and up to older women as well."
There are some international conventions that aim to protect cultural items, and PNG does have legislation to prevent valuable artefacts and relics from being removed from the country.
But there is no specific protection for cultural products like meri blouses or other traditional costumes, which means they can be copied and manufactured overseas.
Ms Maliaki said the meri blouse was unique to PNG and should only made there.
"They can allow them to bring in some products — but such as PNG colours and all this, they should stop them, or put some kind of restriction on how much quantity should come into the country," she said.
"It really isn't fair when we are trying to make quality products, products we make with our own hands and skills."