Why does your new flatware leave black marks on food?

New flatware is unlikely to leave black marks on food. It's possible that you have silverware, not flatware, which is made from a nickel, copper, and zinc alloy that can sometimes leave a blackish residue on cutlery. Try washing the silverware in hot soapy water to remove any residual oils. If the marks persist, it's best to consult the product manual or contact the manufacturer for further guidance.