Fiber-reinforced poly(ethylene terephthalate) sheet is laminated to a sheet of amorphous, adhesive copolyester at a temperature at which poly(ethylene terephthalate) is in a molten state. The resulting composite sheet is useful in making thermoformed articles in which one member is bonded to another member, for example, a face member and a backing member. The different members are arranged so that their copolyester layers face each other. Hollow thermoformed articles bonded with amorphous copolyester adhesive exhibit very good bond strength and minimum distortion.