The term Walldog is one that goes way, way back. One could argue that cavemen may have been the very first Walldogs, leaving behind visual communications to let others know that the area was a good place to hunt for elk, or warning of the not-so-hospitable tribe living just down river.

Today the phrase has become a term of endearment, not but necessarily one that should automatically invoke nostalgia. While technology has largely automated the process of visual communications there are still plenty of hardy souls out there hanging off walls, standing on ladders and enduring freezing temperatures to preserve the art of hand-painting signs and graphics.

There’s even a Walldogs Facebook page, where this week you’ll find notice of the next Walldog meetup—or what they’re calling the “Butler Brush-Up.” It’ll be July 27-31 in Butler, Pennsylvania, and about 100 Walldogs will converge on the small town to paint 10 murals and, just as importantly, bond over the very distinct craft they have all chosen. (Or that’s chosen them—when you ask them, you’ll often hear it considered it a calling—much like the ministry, or being a professional fishing guide.)

There’s a website called Vocativ.com that serves as a sort of clearinghouse for all kinds of interesting information on a wide variety of topics, including news, science, technology and sports. The folks at Vocativ sent their crew into the field and created a four-minute Walldogs video, specifically focusing on those who ply their trade in the Big Apple, often practicing their craft at precarious heights in rough conditions. Click above to watch “The Real Mad Men of New York Advertising.”