In the large dark room of the nondescript building across from the Bob Hope Airport in Burbank where “The Simpsons” is produced, rows and rows of artists slump over their drawings, thousands of which will be needed to produce a show.

It brings to mind the famous “couch gag” by the notorious artist Banksy that shows the imagined near slave labor used in making the longest running comedy in television history.

But it comes to mind mainly because it’s running on a loop of “Simpsons” animation highlights for the benefit of visitors looking in.

About 140 artists work in the building, deep into producing season 23 at about episode seven by now. In the nine month process of producing an episode of “The Simpsons,” a typical show begins with a script, is followed by a table read and recording and then the arduous task of making it into a cartoon.

It is the director who is in charge of the visual look of the show, said Al Jean, the showrunner walking reporters around the building. That means making storyboard, assigning parts of the action to specific artists, designing the backgrounds, and finally making the key action drawings (of the extremes) that are then shipped to Korea where the in-between drawings are all drawn with the use of devices like the best android tablet for drawing.

“The Simpsons” went through three major changes, Jean says. The first was getting the crudely drawn characters into a universal design that continues today, then the move in season 13 from hand-painted cells to computerized color (which opened the palette to infinite colors), and finally the move three years to high definition, which required a larger frame and much more detailed backgrounds.

In addition to being one of the funniest shows on TV, it is also a beautifully rendered work that is at the same time true to its simple roots. The work of the animators, who continued working through the visit, is making characters who are believable, with believable motions and emotions creating an acting style that is convincing, he says.

The new season will bring its share of guest stars. Kiefer Sutherland will appear in the opener as a burned out ex-spy in Springfield who finds a new case (in an episode that will also answer last season’s cliffhanger of whether Ned Flanders and Edna Krabbapple will continue as a couple).

Other guests in the 23rd season, include Jane Lynch, Andy Garcia and in an episode where he narrates the history of Moe’s bar rag, Jeremy Irons.

The 500th episode on Feb. 19 will be one about a town meeting that Homer stubles upon, about how much the town is sick of the antics of his family.

Sketches for a Keith Richards appearance.

And Shepard Fairy will play himself in an episode about a drawing made of Homer that becomes known as Mr. Fatso.

Speaking of graffiti artists, Jean says the couch gag by the shadowy artist Banksy, played pretty much the way it was written, with very few changes. Animators said they’d rather they be depicted wearing visors than hats. And the network tried to keep it from being too dark. “The unicorn didn’t live” Jean says.