3M™ CeQUIN 30F Inorganic Insulating Paper Laminate 5 mil(3+2). 3M™ CeQUIN® IF and IFI Inorganic Insulating Paper Laminates are designed to meet the high-performance requirements of Class 220(R) coil winding applications. CeQUIN inorganic Insulating Paper provide the long-term thermal stability and dielectric strength required for continuous operations at temperatures up to 220°C. The polyester film provides added mechanical strength, improving the overall handleability of the CeQUIN paper, makes it easier to use in coil winding processes.