The immense ice bag, as large as your back yard, probably as large as your condominium, billowed and seethed and slowly raised its metallic cap and then slowly billowed again behind the backs of the tuxedoed guests as they ate their filet and cre me bru le'e at the East Wing of the National Gallery last night. The creator of the motorized ice bag, Claes Oldenburg, barely glanced at his creation, which was inflating, sinking, reinflating as he described the inner workings of the roiling thing.

"That goes back to a period in the late '60s when Gemini was very adventurous," Oldenburg said of his massive object. Gemini, or Gemini G.E.L. as it is formally known, is a print workshop in Los Angeles where artists like Oldenburg, Robert Rauschenberg, Jasper Johns, Roy Lichtenstein, Edward Kienholz and David Hockney worked, defining and redefining art through the '60s, planning "happenings" and sketching political posters.

Adventure is what the 17 artists gathered at the East Wing had been doing with ice bags and air pumps and car doors and paper and ink. History was what was happening at the National Gallery, where their work was about to open as a show and where (a rarity at a place that usually shows work of artists long gone) the guests could applaud the artists and have the artists themselves, not the scholars who study them, stand and receive the applause.

"They'd do anything then," Oldenburg said of Gemini in the '60s. "It was a different time. It was such a daring time. Now, it's a conservative period, very conservative."

And a conservative town.

The invitation for the dinner stated that the attire should be "invention or black tie, but something paper imperative." But in Washington, true invention is rare. There was the odd ribbon or doily gracing the pocket of an otherwise pristine tuxedo, but the majority of the guests stuck with the basics: velvets and satins, black tie and taffeta.

"I'm a little bit disappointed," said Vera Freeman, a manager at Andrews Nelson Whitehead, the New York paper supplier that provided much of the paper for the prints in the exhibit. It was the general lack of paper inventiveness that disturbed her, not the exhibit.

The artists had excuses.

Hockney, bright as ever in a blue blazer, turquoise striped shirt and black and pink striped tie, said, "I didn't know it was black tie." He plucked at his blazer as if his fingers could transform the blue into black.

Rauschenberg, wrapped in a thick poncho and multicolored tie and surrounded by laughing, kissing friends, said, "My paper is hanging all over your walls."

But those who had provided only the curatorial paper rather than the creative paper were much more daring. One museum staffer peeked out from under a papier-ma che' Venetian carnival mask; another from the information office had crafted a collar and belt from the mastheads of easily recognizable newspapers and magazines; and the odd creative soul had fashioned a shirt front out of turquoise crepe paper or a discreet bow tie of red crinkly stuff.

And because these were smart people, some people carried the idea to its conceptual conclusion. Take National Gallery deputy director John Wilmerding, who wore not paper but polyester. What made it legit was that the polyester shirt peeking out of the tuxedo was bright with cartoon frames containing the small wacky figures indigenous to Saturday mornings and youth.

"It's a '60s relic," Wilmerding said.

"It's synthetic," said Los Angeles art museum director Earl Powell, in the voice of someone rediscovering a beloved but obviously immature taste.

"At least Roy Lichtenstein liked it," said Wilmerding.

Off by the giant ice bag, Lichtenstein was laughing, his neck wrapped in a red paper bow tie.