A thermal insulation assembly for a duct through which high temperature fluid, greater than 500 Fahrenheit, passes. The thermal insulation assembly can experience pressures less than 80 kilopascals and can be included in a turbine engine. The thermal insulation assembly includes a first foil layer confronting the duct, a second foil layer spaced from the first foil layer, an insulation layer between the first foil layer and the second foil layer, an opacifier layer provided on the insulation layer, and a reflective layer applied to the opacifier layer.