Diamond dotted Insulation Paper is made of electrical grade Insulating paper coated with B-stage heat curable epoxy resin on either or both sides. The base paper is made from unbleached 100% Sulfate Kraft pulp. It is used in Oil-immersed Transformers for insulation between coils. At high temperature, the dotted epoxy resin melts and paste on neighboring coils to make the electrical conductor as a hard unit.