Thermal insulating materials are considered to be all insulating materials that are capable of trapping still air within their mass. High mechanical strength is often required in many thermal insulation applications; however, it does not significantly affect the insulating properties of the materials. We distinguish which insulating materials offer greater thermal protection by their thermal conductivity coefficient (λd). The lower the λd value, the better the insulating performance of the material. Thermal performance also depends on the thickness of the material — the greater the thickness, the higher the thermal resistance provided by the insulation used.