Wilbur (Jack) Jackson, 78, a printer at The Washington Post from 1940 until his retirement in 1967, died of cancer Sunday at Arlington Hospital.

Mr. Jackson, who lived in Arlington, was born in Newton, Kan., and grew up in Huntington, Ind. He moved to the Washington area in 1935 and worked for an automobile agency until he joined The Post.

He was a member of Elks Lodge No. 15 in Washington for more than 47 years. He was the lodge historian and played a role in having the Elks building at 919 H St. NW declared an historical landmark. He also was a member of Columbia Typographical Union No. 101 and the Knights of Pythias.

He was a member of St. Mark's United Methodist Church in Arlington.

Survivors include his wife, Kathryn B., to whom he was married for 47 years, of Arlington; one brother, Frank, of South Bend, Ind., and two sisters, Bee Jones of Fort Wayne, Ind., and Helen Scott of Chevy Chase.

The family suggests that expressions of sympathy be in the form of contributions to the Memorial Fund of St. Mark's United Methodist Church, N. 25th St. and N. Glebe Road, Arlington, Va., 22207, or to a charity of one's choice.