Solimide polyimide based cellular foam is well established as an excellent thermal insulating material 12 with thermal conductivity values in the order of 0.039-0.046 W/mK. The material can further be “densified” through the process of applying heat and pressure collapsing the foam into a much thinner layer of increased density and improving the insulating properties by as much as ?. Densification can be applied to the foam to compress from a typical foamed density of ?0.4 lbs./cu.ft. to a range from 1 to 10 lbs./cu.ft. while maintaining or reducing the thermal conductivity (i.e. as much as 30% when compressed to 2 to 3 lbs./cu.ft. range). Densification produces a thinner insulating layer (0.25 to 2 mm) that would otherwise be difficult to skive using traditional slitting equipment (>2 mm). The thinner, denser foam retains much of its same cellular properties while being better suited to fit within the smaller form factor of typical consumer electronic devices. Depending on the final thickness of the insulating material desired, the material may be skived before or after densification. The thinnest final thickness commonly requires skiving before densification.