The non-woven glass backing also allows the tape version of this product to pull down flat and tight, even around irregular surfaces such as the "nose" of a coil. The fully cured polyester binder is very flexible. Mica Mat 77959 is a 8.5 Mil thick mica paper tape with non-woven glass reinforcement and PET film on both sides. This construction permits increased mica content per unit thickness over conventionally reinforced, woven glass products, which results in greater voltage endurance protection.