A high voltage transformer including a transformer housing. Internal components and provided in the transformer housing. The internal components are submerged in transformer oil and are provided with insulation for insulating a high voltage winding end. The insulation includes a shield ring arranged above the winding end and a pressboard structure formed in a zigzag pattern arranged around the winding end. The shield ring includes a core covered with a conducting layer and a continuous solid insulation layer outside the conducting layer. The insulation layer includes integrated solid insulation sections of which at least some among themselves having varying thickness. Also a shield ring and a method of manufacture the shield ring.