Though much of today’s advertising has shifted to online popup ads, some old-school techniques are still employed.

One in particular — murals on the side of New York City buildings — is daring, artistic and takes a certain type of person to make. Meet the “Wall Dogs of NYC.”

Image source: Vimeo

Image source: Vimeo

“It is a very human way to get the message out,” a man only identified as Caesar, who is one of these artists that hangs from the side of a building while painting a giant image, said in a video produced by Vocative. “It’s not a little window at the bottom of your computer that pops up. It’s not a commercial in between your television shows.”

Gary Baxter, a sign painter, explained that the term “wall dog” is an old-time nickname.

“Painters like us are essentially chained to a wall all day on our safety line,” Baxter said. “So, essentially, we’re on chains as a dog, and we work like dogs out there.”

Image source: Vimeo

Image source: Vimeo

Wall dogs work in extreme conditions for 10 to 12 hours at a time on a platform that with a pulley system allows them to traverse the wall.

“You’re like a fly on the wall and you get to see everything,” Caesar said.

And the trade really hasn’t changed much over the years.

“Everything we do is traditional. Everything from the paints we use to the way we mix them to the way we rig our walls to the way we pattern to the way we paint,” Baxter said.

Image source: Vimeo

Image source: Vimeo

This method, according to the artists, draws more attention to the message they paint compared to a large poster or billboard because of the craft and detail that’s put into it.

Watch Vocative’s full video giving you an inside look into the life of a wall dog: