Many travelers to the Tibet Autonomous Region might come across piles of stones with religious carvings of scriptures and Buddhist images. Olo Tsering is one of the Tibetan craftsmen behind the prayer-stone carvings. On one of his workdays, he sits focused on a carpet and meticulously carves a religious mantra on stacks of stone plates.

Tibetan nomad Tashi Penpa commissioned the mantra, named Yikgya. Olo Tsering took four days to complete it.

The 46-year-old craftsman, who has been working on the religious carvings for about 30 years, considers his skill to be a valuable gift from him ancestors and strives to pass it on.

In early March, Tibetans revel in celebrations to mark the Tibetan New Year Festival.

Many temples welcome flocks of pilgrims during this time and prayer-stone carvers see this as an opportunity for their work.

"As people get wealthier, the demand for prayer-stone carving is also increasing," Olo Tsering said.

Olo Tsering comes from the Yushu Tibetan autonomous prefecture in Qinghai province and is known in those parts for his skill.

Yushu also boasts the world's largest prayer-stone pile of its kind, the Jana Mani Heap.

Olo Tsering headed to Tibet's regional capital Lhasa two decades ago. He has dabbled in various kinds of work but finally chose to focus on prayer-stone carving.

His pieces include various Buddha images and Tibetan scriptures, such as the famous Om mani padme hum, the mantra of the bodhisattva of compassion, Avalokiteshvara.

The craftsman said the carvings are an important part of Tibetan culture.

"I am the third-generation prayer-stone carver in my family and I hope this tradition will last forever," he said.

Olo Tsering said he has trained more than 10 apprentices, including his son.

"Prayer-stone carving dates back about 1,300 years. It is like a venerable river and I don't want see to it drying up one day," he said.

Olo Tsering's son is in middle school and he trained the boy during the school holidays.

It takes about two years to become a qualified prayer-stone carver, he said.

"Learning how to carve the scriptures requires at least two months. It takes two years for the images," he said.

Olo Tsering said carvers also have to be religious. They must desire to inherit the traditional art, be able to read and write, and work diligently.

Carving a long mantra takes a long time and much energy. A short work of four to six syllables requires several minutes.

"The shortest mantra has four syllables, and I can carve 300 to 400 plates in one day," he said.

For a longer mantra, he can carve four to five pages within a day.

In the past, the skill was mainly carried out by hand. But craftsmen now also use machines.

Carving a 142-page mantra requires 160 stacks of stone plates, Olo Tsering said. It takes more than three months by hand but about 26 days using a machine.

Some orders need several years to complete, such as the Lhasa Kyagyur Chenmo.

Dozens of carvers took part in the major project, which lasted about 16 years. Olo Tsering also spent two years helping them.

While carvers said demand for their work as well as the efficiency of producing them are increasing, Olo Tsering said using more machines means quality has been affected.

Tibetans usually place the prayer-stones on a fixed pile, at spots where Tibetans circumambulate religious relics in a clockwise direction.

Tibetans order prayer-stones to pray for world peace and all living beings, local residents said.

Olo Tsering said he is pleased his work because he is passing on an ancient tradition. He also considers his work as a way to accumulate virtue.

"I have to make a brighter path for my next life and I consider carving mantras to be the same as reading them," he said.

"I never feel tired. The more I carve, the more mantras I read."