Where there’s smoke, there’s stagecraft

Baylee Littrell (front row left), Seth Rudetsky and Rachel York and others star in the musical “Disaster!” where stage fog was used as thick casino air, billowing explosions and smoldering fires below deck at the Nederlander Theater in New York.

NEW YORK — The barometric pressure affects it. So do the whims of air-conditioning systems. Under the wrong circumstances, it could get whooshed into the crowd the moment the curtain rises.

Stage fog is a delicate creature: whether as haze that hangs in the air, a thicker vapor, or the low-lying kind that the lighting designer Natasha Katz calls “Brigadoon” fog: the stuff that wafts like a cloud around the actors’ ankles when it’s kept really cold, and rises higher when it’s not.

“It’s the most elusive of all our materials,” said Katz, a five-time Tony winner who is currently unleashing abundant fog on Broadway in “School of Rock” and promises a different kind of haze in “Long Day’s Journey Into Night” this spring.

Often water- or oil-based, sometimes made with dry ice, fog is difficult to control and as evanescent as theater itself, especially the fast-dispersing variety.

Actors’ Equity has a whole host of guidelines about using it safely. Several Broadway and off-Broadway lighting designers spoke recently about harnessing this most ethereal element.

Danai Gurira’s drama about female captives and soldiers in the Liberian Civil War, at the Golden Theater.

The effect: The fog of war, enveloping the landscape in combat scenes, with haze in the air and chilled fog hovering at ground level.

The designer: Jennifer Schriever: “It started out as a very practical choice to physically carve out the space with light. Then we learned it added depth and dimension.”

The worries: “It behaves differently when there’s a house full of people than when the theater’s empty. It behaves differently if the humidity changes. We had a day where it just very randomly sunk low to the ground. It’s totally inconsistent theater to theater, and in the (same) theater day to day. ... If you’re choking the audience, you’ve done something wrong.”

Andrew Lloyd Webber’s musical adaptation of the Jack Black movie, at the Winter Garden Theater.

The effect: Rock ‘n’ roll fantasy. Stage fog is so essential to the rock-band ethos that even the characters talk about it — twice.

The designer: Natasha Katz: “In the world of rock ‘n’ roll, you want to see the beams of light in the air, and the only way you can see a beam of light is by having — I hate to use this word — a particulate in the air: our version of dust, really. It’s an incredible, incredible tool for us if used correctly.”

The worries: “The hardest thing is getting rid of haze, and even dry ice. You want it to disappear in the blink of an eye, and it’s as if you burned a roast on your stove. It’s very difficult to suck the smoke out.”

Mona Mansour’s play about a woman whose financial collapse can’t dent her faith in fables of perseverance, at Labyrinth Theater Company.

The effect: Smoke and flames from a living-room fire, an illusion created spitting distance from the audience in the tiny Bank Street Theater.

The designer: Bradley King: “Between the fogger and the flickering lights, we make fire. Fog and its compatriot, low fog, the super-chilled stuff that hugs the floor: those two things eat up more tech time than anything else. You can go for a week and just keep tweaking. But it’s so satisfying when you get it right. And I actually think this is kind of working.”

The worries: “One of the biggest problems that I’ve had with fog machines is the sound they make, because they’re actually pretty loud, and when we’re in a space this small, that sort of gives the game away. Ryan Rumery, our sound designer, has a fire sound effect running nearby, and that helps mask the mechanical sound.”

Kyle Jarrow and Lauren Worsham’s glammed-up “rock fairy tale” at Ars Nova.

The effect: Beams of colored light cut through heavy haze in an intimate space bisected by a runway stage, from which fog also makes a brief appearance.

The designer: Brian Tovar: “ ‘The Wildness’ is a rock show, first and foremost. It’s very environmental, it’s very immersive, and fog is immersive. You can step through it. For this show, haze makes light a sexy thing.”

The worries: “The biggest mistake is overwhelming your performers and audience. You really have to find the balance between serving its purpose and everyone being able to enjoy seeing the show.”

Seth Rudetsky and Jack Plotnick’s musical spoof of 1970s disaster movies, especially “The Poseidon Adventure,” at the Nederlander Theater.

The effect: Thick casino air, billowing explosions, smoldering fires below deck. Also clouds and mist. Sample line: “I smell smoke! We have to get out!”

The designer: Jeff Croiter: “The first week of previews, the notes were always like, ‘Can we have more smoke?’ For certain of the explosions, we could not get enough.

“Because these (fog) machines are sitting offstage and up in the air, it tends to fill up the backstage area first. I look onstage, and I say, ‘This looks amazing,’ and then a week later sometimes you hear that the flyman is sitting up 30 feet in the air, and he can’t see because there’s so much smoke. So you make adjustments.”

The worries: “When people in the audience are saying ‘Look at all the smoke’ and not watching the show, it’s probably not a good thing. In this case, it’s funny. In ‘Disaster!’ the smoke was the joke.”