We believe that one should control gradients on high voltage insulators using low resistivity plastics. Longterm space charge build-up, especially in a very cold insulator, cannot be excluded if one has a source of charge. Time constants, given extremely large volume resistance values involved, can be extremely long, which can result in quite unusual voltage gradients. Teflon may also shed pollution, which may end up on the cathode wires as a film, which will increase its resistivity in cold liquid, and may lead to a Malter effect. Show Partial Abstract