This story is part of Forbes’ coverage of Indonesia’s Richest 2022. See the full list here.

Siblings Wijono and Hermanto Tanoko draw more than 60% of their $3.65 billion fortune from Avia Avian, Indonesia’s leading paint maker by market share. Founded by their late father Soetikno Tanoko in 1978 in East Java, the company went public late last year raising 5.76 trillion rupiah ($400 million) in what was the biggest IPO among its Asian peers in 2021.

“We took Avia Avian public to build visibility to support growth in new markets,” Hermanto, the company’s president commissioner, says by video call. It sells in 98 cities across 37 provinces and has plans to expand deeper into the hinterland. It’s also building a new factory in West Java, adding to its two existing factories.

The brothers run a very profitable operation. In the first nine months of 2022, Avia Avian reported a net profit margin of an eye-popping 21.7%—the global average is 6%—on 4.9 trillion rupiah in revenue. Hermanto says the company can deliver such high margins because “we have an integrated business, from upstream to downstream.” Apart from paints, Avia Avian together with its affiliates produces paint cans and machinery and has its own printing facilities and distribution network. For 2022, Hermanto expects the company to log 10% sales growth.

While shares of Avia Avian are now trading below the IPO price, the brothers’ combined fortune got an 11% boost, largely from Hermanto’s thriving portfolio of listed companies under his separate holding outfit Tancorp Abadi Nusantara. In the past year, shares in Tancorp’s bottled water firm Sariguna Primatirta rose by 35%; property developer Jaya Sukses Makmur Sentosa by 130%; and clothing company Mega Perintis by 200%.

Hermanto is keen on acquisitions. In October, his Tancorp Bangun Indonesia spent 151.5 billion rupiah on a 55% stake in Jakarta ceramics maker Cahayaputra Asa Keramik, which he says has the potential to become a global player. “When it comes to acquisitions, we will do it when we believe the company can grow faster with us.”