Abstract: A dry-type transformer, comprises a magnetic core, at least one high voltage (HV) winding, and at least one low voltage (LV) winding inductively coupled to the magnetic core. The transformer is made by determining a shape of an electric field that is generated, 3D printing a dielectric structure shaped to conform to the determined shape of the electric field, and mounting the dielectric structure between the HV and LV windings. A dielectric barrier arrangement for electrically isolating a coil of a transformer assembly from a further coil of the transformer assembly or from a core of the transformer assembly comprises a first dielectric structure having a first cylindrical dielectric structure extending along a longitudinal axis (L).