Just knock it off, would ya?

Imitation may be the sincerest form of flattery, but when it comes to design, it can also be the most insulting form of commerce.

Take the classic Ball Clock created by George Nelson, a master of midcentury industrial design. A simple configuration of metal rods and painted wood, the 1948 timepiece, then priced less than $25, was an icon of peacetime that transformed the structure of an atom into a whimsical decoration. On Sunday, Los Angeles Modern Auctions sold a vintage Ball Clock for $1,300. As the hammer fell on the final bid, Ben Storck of Modern One asked: “Don’t people ever tire of that clock?”

Apparently not. The Ball Clock is one of the most recognizable -- and most copied -- products of the fabulous ‘50s. A few years ago, it was part of a large collection of Nelson designs brought back to the market by Vitra, an Italian firm that licenses and reissues classic 20th century furniture and accessories and now maintains a retail location in Santa Monica. At $250, the Vitra edition, also sold through catalogs and websites such as Design Within Reach, is built to the same specifications as the original.

Now, however, anyone with 36 bucks and directions to the nearest Urban Outfitters can pick up an almost identical version in fluorescent colored plastics by Momo Design that comes in a retro-styled package citing Nelson as an inspiration. Momo owner Garret Glaser grew up with a Nelson Starburst clock in the family kitchen. He also adapted that timepiece as a “tribute to the lasting impact of midcentury design.” Both Momo clocks have been out-of-the-box successes; in less than a year on the market, combined sales have reached nearly 100,000 pieces.

Though this is good news for cash-strapped Modernism fans, it may not be the best news for the Nelson estate, which receives recognition but no royalties from Momo. It also reveals much about the landscape of today’s copycat culture. Today, it is possible to buy home decor items that look like some of the greatest designs of the 20th century, ranging from cheap counterfeits to quality merchandise said to be “inspired by the original” but altered enough to avoid charges of design theft.

According to Mark McMenamin, senior editor of the trade publication InFurniture, the floodgates opened in 1995, when home decor pulled out of its recession and became a hot product category. “Neophytes who knew nothing about furniture built businesses based on other people’s research and development, picked up catalogs and sent pages to factories in China.”

As furniture sales soar, more midcentury designs are likely to be copied because they are proven. “We’re looking with affection to the comfort and innocence of the ‘50s and ‘60s,” adds McMenamin. “For those who didn’t live through those eras, these designs are new, and it’s much easier and more cost-effective than actually hiring a designer to do truly original work.”

Unlike creations of the fashion industry, which does not recognize design as a protected work of art (except, of course, in France), furniture and home decor products are afforded a level of protection through a complicated web of sometimes overlapping design and utility patents, trademarks and copyrights. Although these are deterrents, there is a huge gray area in which the manufacturers of designer impostors operate. Consequently, copying is rampant within the industry.

“As a society, we don’t encourage brazen copying, whether it’s trademark infringement or your children cheating on a test,” says attorney Susan E. Farley, an intellectual property specialist from Heslin, Rothenberg, Farley & Mesiti in Albany, N.Y. Proving that a design has been used illegally, however, is a laborious, often expensive pursuit. Though many manufacturers register designs before beginning production, many copycats knock off preproduction samples based on photos or trade show displays. Digital photography, e-mail and offshore manufacturing combine to make copying a design so easy that it is not uncommon for originals and imitations to hit retail simultaneously.

When lawsuits do occur, infringement claims can become impossibly complex. “If the motivation is trying to benefit unfairly from someone else’s design, effort and goodwill, it clearly is wrong,” says Farley.

It also hurts designers, who may be unwilling to invest in the lengthy and expensive process of making prototypes. Farley contends that such reluctance will eventually limit consumer choice. “We want to have nice-looking things,” she says. “But we’re all going to be sitting on gray bean bag chairs one day if we don’t reward the risks incurred in creating original design.”

Following the lead of the film and music industries, which have been trying to drum into our collective heads the idea that piracy affects everyone involved, there is a new movement afoot to quash knockoffs in the home decor industry. Since 1994, the Foundation for Design Integrity, an organization formed by three Los Angeles designers, Sally Sirkin Lewis, Bradford Stewart and Michael Sorrentino, to protect the interests of designers, has served as a resource center for manufacturers embroiled in legal battles with copycats. In addition to making busts, the group wants to send a message to consumers.

“Our goal now is to educate the public about the fact that the person who created the design has moral and legal rights to profit from it,” foundation president Eleanor McKay says. Last year, a $3,000 copy of the $12,000 Rinaldi chandelier designed by her husband for their company, Niermann Weeks, appeared in a Neiman Marcus catalog. “It was a fraud,” McKay says.

She is more lenient about individual decorators who hire local craftsmen to copy designs and furniture manufacturers who work in a respectful tradition. “If an educated consumer can look at a product and say, ‘It does remind me of the original Stickley piece, but isn’t it clever how this designer has tweaked it by using different proportions or a different material?’ we regard that as OK, because that is an hommage.”

The design world depends on such inspiration and refinements to move forward. Since the Industrial Revolution made mass-produced furniture possible, designers have used scale, proportions, materials and manufacturing techniques to redefine classic shapes for contemporary times. In the case of Edward Wormley, whose postwar designs for Dunbar have become highly prized, it is easy to trace the lineage of his sinuous klismos chair back to antiquity. Similarly, Isamu Noguchi’s paper Akari lamps are sculptural re-imaginings of Chinese lanterns.

The distinctive quality of the best midcentury designs, however, is that they defy such easy categorization and define something unique. Noguchi’s classic coffee table, with a base made from two identical wood forms set in opposition to each other, seems to have no precedent. The Herman Miller Co., which manufactures that Noguchi table along with Nelson and Eames designs, has launched Get Real, a campaign created to clarify the differences between authentic designs and imitations.

An exhibition of signature Herman Miller products that has traveled to 15 U.S. cities for trade shows and displays at dealers such as Jules Seltzer in L.A., Get Real is an attempt to market the legacy of American design. Marge Mojcak of Herman Miller for the Home, a division launched in 1994 to reissue classics such as the molded plywood Eames chair, says, “It’s the relationship between the designer and manufacturer that defines authenticity.”

McMenamin says the Get Real campaign sends an “absolutely effective” message to copycats. For the public, he believes, it’s a different story. “Most people just want the look. It doesn’t matter to them if it’s original and that the original designer or their estate isn’t getting paid, because they don’t that think that far down the food chain.”

This popularity of the postwar look is something that even the most farsighted 20th century designers could not have anticipated. Many of the products that have come to symbolize modern designs, such as Eames chairs and Nelson’s Ball Clock, were created in large quantities with the same built-in obsolescence as the fin-tailed automobiles of the era. Fifty years from now, scholars might argue over whether these mass-market designs have the artisanship to be considered antiques.

Expressing the spirit of the times in which they were made, they were intended for a family room or kitchen, not conceived as heirloom pieces. They might have gone the way of Mickey Mouse watches -- in other words, cute collectible Americana -- had something curious not occurred.

In the 1980s, vintage furniture boutiques, including Skank World and Futurama, began popping up in Los Angeles, causing a reassessment of midcentury design. A feeding frenzy followed, and Eames chairs and Nelson clocks were elevated from wood-paneled rooms to museum pedestals. Once 1950s kitsch, they became 1990s cachet.

Predictably, early collectors moved on to more rarefied delights: the couture designs of Hollywood Regency and the exquisite woodcraft of George Nakashima. The evidence was clear at Sunday’s Los Angeles Modern Auction, at which two George Nelson coconut chairs, triangular fiberglass constructions suitable for Austin Powers, sold for $1,500. Midcentury modern, it appears, has begun to look hopelessly mid-America.

For a new generation, 50 years after the heyday of midcentury, this matters not a bit. There are even those who argue that the populist ideals of Modernism furniture -- using new materials and technologies to create goods priced for the average family -- might embrace the new wave of contemporary products created in the midcentury style.

“The Astro Clock is making modern design affordable,” says Momo’s Glaser. “And the people who can buy an original or a reissue can tell the difference.”

Herman Miller’s Mojcak isn’t so sure Modernism needs to be reinvented. “There is a wire chair from Urban Outfitters based on Eames designs that was recently written up in a magazine. They said isn’t it great, design for the masses, just what Charles and Ray [Eames] would’ve wanted,” she scoffs. “If they had, they would’ve planned accordingly.”

Adamo DiGregorio contributed to this report.