Features The New York-based Sudanese artist looks back on a lifetime of experimentation in a multi-city retrospective.

Mohammad Omer Khalil with his work in Common Ground at Blackburn Study Center, New York (photo Leslie Jean-Bart, courtesy the artist/Blackburn Study Center)

In 1964, Mohammad Omer Khalil made his first etching. He was initially dubious about its chemical process, hesitantly dipping his fingertip into the acid to test its safety. But this small print, cautiously rendered during his studies in Florence, Italy, marked the start of a decades-long trajectory toward becoming a master printmaker, working across continents.…