'foil-backed' originates from English, specifically by combining the noun 'foil' (a thin metal sheet) and the past participle 'backed' (from the verb 'back', meaning 'to support' or 'to provide a backing').

'foil' comes from Old French and ultimately Latin 'folium' meaning 'leaf' (later used for thin metal sheets), while 'backed' is from the verb 'back' (Old English 'bæc' meaning 'rear' or 'support'); the compound 'foil-backed' is a modern English formation combining these elements.

Initially, 'foil' referred to a thin leaf (from Latin 'folium'); over time it came to mean a thin sheet of metal, and the compound 'foil-backed' developed to describe objects that are lined, supported, or coated on the reverse side with such a sheet.