Commemorative plaques cast from brass are a characteristic art form of the Benin culture of West Africa. Some scholars, noting that the oldest surviving plaques date to the 1400s, hypothesize that brass-casting techniques were introduced by the Portuguese, who came to Benin in 1485 A. D. But Portuguese records of that expedition mention cast-brass jewelry sent to Benin' s king from neighboring Ife. So it is unlikely that Benin' s knowledge of brass casting derived from the Portuguese.
The statement 'The Portuguese had no contact with Ife until the 1500s' most strengthens the argument.