DETROIT (AP) — A private reception is scheduled for the unveiling of a permanent fresco inside downtown Detroit’s Cobo convention center.

Cobo Art and the Detroit Regional Convention Facility Authority say artist Hubert Massey will be finishing the last strokes of his fresco during tonight’s event. A public event celebrating the artwork will be held Sept. 23.

Massey began working last year on “Detroit: Crossroad of Innovation.” It is at the entrance to Cobo’s Grand Riverview Ballroom.

The 30-foot by 30-foot piece depicts Detroit in a timeline of the city’s heritage. An advisory committee was established to help Massey identify key themes from Detroit’s history and culture to be featured within the fresco.