Final answer:
In the scenario where Rockwell International both sold a printing press to Zimbabwe and purchased commodities from them, the exchange is known as counter purchase or offset trade, a form of barter.
Step-by-step explanation:
The scenario described in the question is an example of a countertrade, specifically a form of barter known as counter purchase or offset trade. In this situation, Rockwell International sold a printing press to Zimbabwe and then agreed to purchase ferrochrome and nickel from Zimbabwe, eventually selling these goods on the world market. This type of trade involves a reciprocal exchange of goods rather than the use of money as an intermediate transaction.