As business freebies go, a trip to Brazil sounds like a boondoggle of the first order.

A "three martini lunch" would be considered a prudent investment compared to a week in South America.

But as a result of such a junket $250,000 worth of Brazilian furniture will be in the Scan stores next spring. Emeralds, opals, amethysts, aquamarines and topaz will be for sale in the Melart jewelry stores and other Brazilian gems in the W. Bell catalogue, and even Brazilian auto tires and wheels will be avaiable at Universal Imports.

Representatives of all four firms, along with executives of 100 other East Coast companies, were flown to Sao Palo recently for Brazil's first export fair in five years.

Brazil shipped $1.8 billion in exports to the United States last year, mostly commodities like coffee, sugar, cocoa and orange juice concentrate. This year for the first time the two countries are expected to come close to a trade balance.

Brazil's aggressive push for more imports, however, is colliding with U.S. balance of payments problems. This week G. Fred Bergsten, assistant secretary of the treasury for international affairs, is in Brazilia for exploratory talks on trade between the two countries.

Faced with U.S. import levies on sugar, the Brazilians are emphasising other goods in their trade development.

Before the trade fair the Melart stores were handling some Brazilian gems. Ivan Gorman, director of store operations for the 14-unit chair, headquartered in Silver Spring said.

"This will solidify our relationship", German said. He added that the mechanics of direct importing were relatively simple - mostly a matter of establishing credit.

"If you give them a sizable order and you turn the merchandise and you reorder, it works very easily," he said, stressing that the volume of business has to be big enough to justifying going abroad.

Although Brazil ranks behind Colombia in the quality of its emeralds, it is the jewelry trade's best source of semiprecious stones, he explained.

Importing the stones "loose" and then mounting them gives Melart an opportunity to offer better prices, Gorman said. "You can get better value as a retailer," he added.

Semiprecious stones were on the shopping list of Walter Bell, who heads the W. Bell catalog showrooms. Bell also shopped the Rio de Janeiro trade fair for silver place and leather goods, mostly briefcases and luggage.

Bell, who has been importing items for his catalog for several years, emphasized the importance of shopping and sampling the merchandise of unfamiliar sources to be certain it meets quality standards.

The necessity of careful quality assessments was mentioned also by Robert Gowell, manager of the Scan stores and vice president of Greenbelt Consumer Coop, the company that owns the 10-store, $19 million-a-year business.

Scan's first experience with Brazilian furniture was "a disaster" because of quality control problems, Gowell admits.

"We went wondering whether we would buy very much" and came back with a $250,000 in furniture on order, he said.

He said Scan, which imports 80 per cent of its furniture and gets most of that from Scandinavia, is buying mostly leather upholstered furniture such as sofas and seating, plus a couple of desks, dining room furniture and easy chairs.

Brazil was once a major source of rosewood furniture, but that wood has become so rare that even the Brazilian manufacturers have trouble getting good rosewood, he said.

But in leather upholstry, Brazil is a prime source, he said, producing sofas that can sell for $500 to $650.

"It's not the cheapest leather furniture we ever bought, but it certainly is favorably priced," he said.

Like leather, rubber is another abundant South American resource, and tires are among the Brazilian items being imported by Universal Tires. Several European tire makers have plants there, explained Universal's Joel Gorick.

Brazilian manufacturers also supply replacement wheels for foreign cars. In addition to the manufacturers who had booths at the Sao Paulo fair, a computer located other suppliers, Gorick said.

Today Is Sunday, the new Sunday newspaper supplement created by Warren Adler and Smith Bagley, will show its pilot issue in The Star on Sunday.

This is strictly a prototype: actual production is slated for March, says adam-turned-author Adler, who is editor and vice president. Partner Bagley is publisher and president. The Adler and Bagley families each own half the magazine.

Designed to compete with Parade and Family Weekly. Today Is Sunday differs from its rivals in size, production method and financing.

Rather than a rotograveure tabloid, Today Is Sunday will be a full-size newspaper, printed offset.

The other Sunday supplements sell advertising, print the magazine, then distribute it to newspapers, which stuff it into their Sunday papers, mostly for the benefit of having a fatter, better balanced weeked package.

Today Is Sunday will be printed by the subscribing papers on presses and paper that meet the magazine's specifications, which means not necessarily in the newspaper's own plant.

Adler and Bagley will provide client papers with a ready-to-print package of news and national advertising with open slots for local ads.

The newspapers will pay Adler and Bagley a fee, based on the paper's circulation.

The papers get the revenue from the national advertising - which will be sold by the supplement - plus any money they can make selling local ads for the open slots.

This combination of local and national advertising is supposed to make the supplement more attractive than Parade or Family Weekly, which bring in very little revenue but lots of readers.

The biggest national advertiser in the pilot issue is Winston cigarettes, a product of R. J. Reynolds Tobacco, Bagley is the grandson of R.J. Reynolds.

The local advertisers in the pilot include Woodies and Garfinckel's, some of the same businesses that would advertise in a paper's own Sunday magazine. How the new supplement will avoid cannibalizing; an existing magazine is unclear.

Adler says presentations on the publication have been made to publishers in the top 50 newspaper markets and a circulation of three to five million is projected for the first year.

The editorial package for Today Is Sunday is described as "personality oriented" and the formula calls for a front page interview and color picture with a big name - President Carter for starters.