He died of congestive heart failure, his son Henry said.
Mr. Kupjack's miniature rooms at the Chicago museum -- 30 shadow-box settings ranging in style from the Colonial period to Art Deco -- were widely admired when they first went on public view at the 1939 World's Fair. The rooms were designed by Narcissa Niblack Thorne, widow of James Ward Thorne, a Montgomery Ward & Company department store heir, who sent them to the Art Institute after the fair closed in 1941, and eventually donated them to the museum.
Before attending a memorial service for Mr. Kupjack at the museum yesterday, Marshall Field 5th, chairman of the museum, said by telephone that the rooms had been on view at the museum most of the time for 50 years and "they remain one of our most popular exhibits."
Mr. Kupjack went to work for Mrs. Thorne in 1937. After reading an article in Life magazine about the European-style miniature rooms she had devised using antiques, he sent her, unsolicited, a miniature chair with a cane seat and a plastic plate and goblet he had made."Mrs. Thorne telephoned my father," Henry Kupjack said yesterday. "She asked him how he knew she couldn't find any canework and where he had bought the glass plate and goblet. My father told her the plate and goblet weren't glass but Lucite -- plastic. And she replied, 'How would you like to come and work for me.' "
Mr. Kupjack was born in Chicago, where he attended art classes at the Art Institute for a decade, beginning when he was 8 years old. He attended Crane College. During World War II, he served as a lieutenant commander and commander in the Office of Naval Research in Washington, making orthopedic instruments, 13 of which are patented. In Museum Collections
After he left the Navy in 1948, he worked mostly for Mrs. Thorne until shortly before her death in 1966. In 1959, he was commissioned by the American Institute of Decorators to produce 17 miniature rooms, copies of important settings designed by such interior decorators as William Pahlmann and Mrs. Henry Parish 2d.
Mr. Kupjack went on to produce more than 700 period-style miniature rooms from his studio in Park Ridge, working for corporations and collectors seeking traditional rooms with doll-house-scale furnishings one-twelfth normal size. His rooms are in the collections of the Henry Francis du Pont Winterthur Museum in Delaware, the Forbes Magazine gallery in New York City and the Palm Springs Desert Museum in Palm Springs, Calif.
In addition to his son Henry, of Chicago, Mr. Kupjack is survived by another son, Jay, of Park Ridge, and a brother, Raymond, of Sante Fe, N.M.