TV PREVIEW

“The Office” series finale, 9 p.m. Thursday NBC

An old index card reads: Original. Real. Poignant. Those were the first words Greg Daniels jotted down a decade ago as his guide in adapting the daft British TV series “The Office” for an American audience.

The ideas on the flimsy card stock proved enduring. They helped the unconventional workplace comedy about a humdrum band of paper company employees stand up to the radically shifting fortunes of a major network and a punch-to-the-gut exit of a big-name star.

But it’s now time to put the paper away as “The Office” prepares to shut its doors for good on Thursday.

Nearly canceled after a lackluster premiere in 2005, “The Office” rebounded and later grew into the network’s highest-rated scripted series, frequently pulling in more than 9 million viewers for its season premieres. An early adopter of the mockumentary style, the show became famous for its fishbowl glimpse at the everyday-looking folks of Scranton, Pa. The show has garnered more than 40 Emmy nominations — winning once for comedy series.

Its end signals a major turning point.

“It’s very emotional — not to sound too Michael Scott-y,” said Daniels, in a reference to the Steve Carell character.

Part of the final season’s conceit has been tearing down the fourth wall. At last, TV viewers get to see the documentary crew that has been skulking around Dunder Mifflin all these years. Their documentary is set to air and critical reviews are starting to come in.

Criticism of the show has been brewing for years and only intensified with the Season 7 exit of Carell. The cast doesn’t pretend it was a smooth transition.

“It was a tremendous blow to the show,” says Rainn Wilson, who plays power-obsessed Dwight Schrute. “It took us awhile to find our footing. There’s been a number of bad episodes but also really good ones.”

Daniels admits that ending the show with Carell’s exit might have been the way to go.

But other cast members were under contract, and “The Office” remained one of the network’s top-rated Thursday shows — so it carried on.

There would be more changes: Mindy Kaling, a writer-producer-star of the show, left at the end of the eighth season to headline her own comedy on Fox; Wilson was set to split off for his said spin-off; meanwhile, John Krasinski, who plays sardonic nice guy Jim, and Helms were juggling burgeoning movie schedules.

“It’s like any other thing in life, any experience — from listening to a song to watching ‘Les Miserables’ to the best job of your life: It has to end sometime,” Krasinski says.

The key cast members agreed to return for a ninth and final season — allowing Daniels to dump an idea of a rebooted season that would have introduced a heap of new characters. It’s an ending that’s bittersweet for longtime viewers.

“One could really feel the executive suits just sort of dragging the lifeless body of the show across the finish line,” says Andy Greenwald, who writes about the show for Grantland.com, an online sports and pop culture magazine. “But I do think the show, as a whole, has made a mark on the American TV comedy by paving the way for a lot of the intelligent, witty and urbane humor we see in some half-hours today.”