"In those days you could get away with being self-taught in design," he said. "I moved sideways through a couple of ad agencies into an art studio and just started applying for new jobs."
In his early 20s, after working as a designer for Auckland firm Artspec, he went freelance for a couple of years, then he and his wife spent a year travelling and working in Australia. When he came back he rejoined Artspec for a couple of years and then went to work for three years at corporate branding company Grafikos. The travel bug bit again and he finished up spending time with Vickers Design in San Francisco as a designer/illustrator, before rejoining Grafikos.
In 1994 he went permanently freelance, working mostly with advertising agencies and other designers. As Nzo Industries has grown, he continues to consult on design projects, but mostly focuses on small to medium businesses in New Zealand and Australia.
The couple shifted to Rotorua in 1997.
"I was a keen mountain biker and Glen had been designing products for apparel companies, and we wanted to do something that would use our skills in our own business," he said.
"We decided on mountain biking gear because that was where we felt there was a gap. It was an opportunity to make things in a market that didn't have much in the way of product then."
Nzo focuses on technical bike shorts and also does some casual wear: "We're not chasing the various high-end performance racers or downhill riders looking for protective gear - just sports riders who do trail riding for fun."
Nzo makes its key products in New Zealand, with a few peripheral products in China. The company had previously manufactured all its products in China.
"But manufacturing there doesn't suit the size of business we are, we're too small - you need the volumes," he said.
There were a lot of challenges to manufacturing in New Zealand and it was more expensive, but it meant the brand story was stronger, he said, and the market was now much more competitive than 20 years ago.
"It's the biggest section of the market, but it's also the most well-catered for now. There are dozens of very large international brands that we are competing against. There's no shortage of product or channels to buy it through. If somebody chooses to buy our shorts, it's because there's something about our story they like."
The company has a strong internet-based business, with its only physical retail outlet a partnership with local retailer Craig Corbett in Nzo / Ride Central, in Amohau St, central Rotorua.
Mr Corbett said the Nzo riding short had been around in essence since the late 1990s.
"It has exceptional style, is hard wearing and is still sought after by all ages, males and females," he said. "Gaz is a creative guy who thinks outside the square and is able to turn that into practical products."
Mr Sullivan said the business was still hard work.
"But by and large it's worked. It's provided a really fantastic period of our life."
Mr Sullivan is well-known in Rotorua mountain biking circles and served for several years as president of the Rotorua MTB Club.
He is also a partner in information website www.riderotorua.com with Rotorua businessman Greg Brown, who owns the Pig & Whistle and Capers cafe. The site operates on a non-profit basis, with all revenue going back into supporting local biking.
Mr Brown, who is also the founder and chair of the Rotorua Trails Trust, said Mr Sullivan had many special qualities.
"Probably the foremost quality is he's very creative. There's no question he's put a lot into the local mountain biking scene."
Gary Sullivan:
* Role: Co-founder/co-owner Nzo Industries
* Born: Auckland, New Zealand
* Age: 58
* First job: Advertising copywriter
* Recently read: Travels with Charlie by John Steinbeck
