Rejection is a hard experience - but acceptance is sweet. That's what pop artist Peter Max says about the installation of the 160 cosmic and flowery bilingual border signs he designed.

They were dedicated yesterday in ceremonies on the Ellipse, three years after they were painted and refused by the U.S. Customs Service. Officials felt they symbolized the drug culture of the 1960s.

"I'm extremely pleased to present these wonderful paintings," Max smiled. "This is just the beginning of what I can do for this country which I love so much."

Max, 41, whose family fled Nazi Germany in the 1930s, also presented a painting of the Statue of Liberty to Jeff and Annette Carter, the president's son and daughter-in-law.

In accepting the 4-by-8 foot painting of bold greens, blues and oranges, Carter said it was appropriate that similar dedication ceremonies were being held in Mexico City and Ottawa for the 160 signs that will be posted along the Mexican and Canadian borders.

Later, he said he had been a fan of Max's since 1972 when the painter presented a painting to then-gov. Jimmy Carter.

Annette Carter said, "What I like about his work is that it has a lot of emotion. We have one of his paintings ("Peaceful Planet") in our room (at the White House)."

Also on display were the seven morals used as the models for the 160 border signs. The sign project was rescued by Jay Solomon, head of the General Services Administration in the Carter administration.

"We found them in warehouses," he said, "and I wanted them used. They're beautiful works of art. Some of the people in the previous administration were opposed to them."

The brief ceremony also featured short speeches by Canadian Ambassodor Peter M. Towe and Mexican Ambassodor Hugo B. Margain, and music by Canadian, Mexican and American groups.

Also attending were Max's parents, Mr. and Mrs. Jacob Max; his children, Adam, 14, and Libra, 11; his companion, model Roseanne Vella, and Swami Satchidananda, a friend the painter brought to New York and helped set up as founder of the Integral Yoga Institute.

At the end of the ceremony Max, surrounded by the family and friends, said, "I have a great love for this country. Sometimes it's nice to show people what a wonderful land this is."