WHEN CRITICS of contemporary stamp design get together they're likely to start grousing about the "Disneys" that some of the newly independent countries have been issuing.

Some countries have been issuing stamps featuring Walt Disney cartoon characters. To many traditionalists these stamps are money-raising schemes designed more to loosen the purse strings of youngsters than to speed the mails.

The U.S. Postal Service hasn't gone that far with its popular, brightly colored commemoratives. But the just-released design of a planned joint issue with Australia is likely to test the patience of many who decry the new issues as "stickers."

The stamp features cartoon characters. One of those is none other than the eagle, the animal most often portrayed on U.S. stamps.

Until now, the USPS has revered the eagle, and it has always been depicted in realistic, if not glorified, views.

To celebrate the Australian bicentennial January 26, however, both the United States and Australia have agreed to a joint issue that will feature the national symbols of both countries -- the American bald eagle and the Australian Koala -- depicted as cartoon-like characters.

The new stamp, says Hugh McGonigle, a Postal Service spokesman, is going to be one of those stamps "you like or you hate."

It does mark a departure from U.S. stamp policy by using cartoon characters, he said. "The conventional wisdom here has been that Americans like conventional stamps," McConigle said.

The Australian stamp may help "loosen us up," he added. Many of the designs that traditionalists have initially disliked, such as the "Love" stamps, have gone on "to sell like crazy," McGonigle said.

The artist chosen for the joint issue is Australian Roland Harvey, a graphic artist well known down under for his children's books. On the stamps, his central figures are of an eagle wearing a vest of the Stars and Strips and the Koala tipping his bush hat and sporting a vest of green and gold, the official colors of his land.

Both are embracing each other in celebration of the 200th anniversary of the first European settlement of Australia. The U.S. version of the stamp is a 22-cent commemorative and the Australian, a 37-cent stamp.

The primary difference in the two stamps is in their typography, with the American stamp proclaiming "Happy Bicentennial, Australia!"

The stamps will be issued in joint ceremonies in Sydney and Washington, the 19th time the U.S. has issued a joint stamp with another country. The issue will be marked by special cards, called maximum cards, and folders carrying a block of four of the stamps. The U.S. card and folders were designed by syndicated editorial cartoonist Pat Oliphant, a native of Australia.

Oliphant produced a design for the stamp, but the Citizens Stamp Advisory Committee found his design impractical and converted it into the card, according to McGonigle.

Additional details on the first-day ceremonies will be announced later.

Another of the many new U.S. stamps promised for next year will debut in Atlanta in January, and the details for that ceremony have yet to be concluded.

The stamp, also a 22-cent commemorative, will mark the 200th anniversary of Georgia's ratification of the Constitution. The vertical stamp, which shows an oak tree rising against the Atlanta skyline, was designed by Georgia native Greg Harlin of Annapolis.

The stamp is the seventh in the Constitutional series which began earlier this year and will include a stamp for each of the 13 original states. The commemorative for Maryland is scheduled to be released in Annapolis in February and the Virginia stamp on June 25 at a site yet to be selected.

Many details of the just-announced 1988 stamp schedule remain uncertain, in large part because the Postal Service is expecting a rate change to be announced in March. It has, therefore, announced rates for stamps only through the March 22 Knute Rockne stamp honoring the famed football coach.

Bill McAllister is a member of The Post's national staff.