A thermoforming methodology for laminated thermoplastic sheets which preserves the class "A" finish and high gloss thereof. A thermoformer has a vacuum box component which includes a mold, and a pressure box component which is selectively sealable in relation to the vacuum box component. A heated laminated thermoplastic sheet is placed in the thermoformer, the class "A" side thereof facing away from the mold, and the thermoformer sealed. Vacuum is applied to the vacuum box component and simultaneously air pressure is applied to the pressure box component, including application of chilled compressed air, resulting in forming of the sheet on the mold and controlled cooling of the sheet which preserves its class "A" finish and high gloss.