Foil backed with paper, plastics, or other materials remains in this heading as long as the aluminum layer does not exceed 0.2 mm and the backing is subordinate to the foil. If the composite article takes on the character of a product classifiable under another heading — for example, a multilayer packaging film where the aluminum is a minor component — classification may shift. The essential character test and the relative thickness and function of each layer guide the analysis.

Rolled-only foil (760711) has been reduced to thickness by rolling and has received no additional processing beyond that. Further-worked foil (760719) has undergone additional operations such as annealing, slitting to non-standard widths, embossing, or coating that go beyond simple rolling. The distinction matters because further-worked foil often commands a different price point and may face different duty rates.