An insulation (10, 100) and an insulated article (40, 56, 62, 82) having improved properties for use in a high temperature combustion environment. The improved insulation may include composite particles (18) of alumina and zirconia-hafnia exhibiting micro-cracks that remain contained within the particles and do not extend into a surrounding binder material. The improved insulation may be a vapor resistance layer (VRL) top coat (80) disposed over a layer of mullite-based ceramic thermal insulation (72) and may be anchored to the thermal insulation by extending into pits (79) formed in the surface (S′) of the mullite-based insulation. Porosity and thickness of the top coat may be controlled to provide compatibility between the elastic modulus of the zirconia-hafnia top coat and that of the underlying mullite-based insulation.