To some observers, the Double Goose T-shirt is reminiscent of vendors in Bangkok's Chinatown going about their business nearly 70 years ago.
Double Goose T-shirt's core products and the brand remain unchanged since its establishment in 1953, though the business has catered to shifts in consumer demand, style and business environment.
Similarly, Chang Dao flip-flops have been around for the same duration with almost no change in design, branding and target customers.
Despite the old image, both companies have sold 100 million pieces each over the decades. This is largely attributed to their unique style, quality and affordable prices.
Their products are made of natural materials and have similar target customers, ranging from age 4 to 80.
The two brands recently collaborated on a unique partnership by rolling out "Chang Dao: Double Goose Legendary Edition" for fans.
Each set comprises a pair of Chang Dao flip-flops with the Double Goose logo and a Double Goose white classic T-shirt featuring both Double Goose and Chang Dao logos.
Some 10,000 sets of this limited edition are available at www.Thailandpostmart.com.
"We never knew each other before, but with many similar traits, we started talking over the past three years," said Chakrapol Chandavimol, general manager of Nanyang Marketing Co, the marketer of Chang Dao flip-flops.
"We're producing this limited edition because we want to inspire everybody to know these two brands, which are 69 years old, can survive despite the economic problems, so why can't others?"
According to Mr Chakrapol, although customers may not see much change in the flip-flops, the company has made many manoeuvres internally to operations, customer service, employees and cost management.
"Chang Dao flip-flops remain popular because they are durable and have a unique style," he said.
"It is not about fashion, which comes and goes in a short period of time."
Dusit Meearee, 59, a farmer from Nonthaburi, said he's been a customer of Chang Dao since he was a child for two reasons: the products' durability and quality.
"I am also a regular customer of Double Goose," said Mr Dusit.
"Double Goose was probably the first white T-shirt available in the Thai market. The reason that brand remained around until now is the product is comfortable to wear. It is also very durable."
Khunakorn Dhanasarnsombat, managing director of Thailand Knitting Factory Co, the producer and marketer of Double Goose apparel, said the collaboration with Chang Dao aims to make Thais proud of Thai brands, as well as to lure more Gen Y and Gen Z customers.
Just before the collaboration, Double Goose changed its logo for some items, extended certain product lines and colours, as well as opened shops at some branches of The Mall.
"Chang Dao and Double Goose brands remain committed to building our status in the Thai market, hoping to stay with Thais for many years to come," said Mr Chakrapol.