Within a flat in northern Tehran, concealed from the public eye, Sean proudly showcases the tattoo motifs crafted by his students, each meticulously etched onto silicon canvases.

The 34-year-old opened the studio only eight months ago, aspiring to share the art of tattooing that over the years has largely thrived underground in the Islamic republic.

"All tattoo artists in Iran usually work at home," Sean, using his artistic nickname, told AFP in his studio.

"We risked a lot this year by opening this place and turning it into an academy."

While Iran has not explicitly banned tattooing, conservatives still view the practice as linked with immorality, delinquency, and Westernization.

Yet tattoos have gained popularity in recent years in the country, with many young people proudly displaying their ink in public.

Seeing the growing trend, Sean opened other studios in the southeastern city of Kerman and the resort island of Kish.

Now, he has more than 30 students eager to learn the craft, which he describes as a "bottomless art".

"All sorts of people now are doing tattoos," said Sean, who has been a tattoo artist for 17 years.

In the past, he said, "people wanted something small, simple, that no one can see."

"But now they're saying 'Ink me up'."

'Satanic and obscene symbols'

In recent years, some Shiite scholars in Iran have declared that tattoos are not forbidden under Islamic law.

"Tattooing is not forbidden, provided that it does not promote non-Islamic culture," according to the website of Iran's supreme leader, Ayatollah Ali Khamenei.

Despite the growing acceptance, there are still some in Iran who frown upon the practice.