A mandrel for electroforming printing screens, the mandrel comprising: a mandrel plate onto which metal is to be deposited to form a printing screen, the mandrel plate including a main deposition surface onto which metal is to be deposited to define a main body of the printing screen, at least one pair of edge sections at opposed edges of the main deposition surface which include edge deposition surfaces which extend out of a plane defined by the main deposition surface onto which metal is to be deposited to define attachment elements of the printing screen, and corner sections at respective corners of the deposition surface; non-conductive elements, as edge elements, which are disposed at the edge sections such as to define an extent of the edge sections; and non-conductive elements, as corner elements, which are disposed at the corner sections such as to shield the same and define an extent of the main deposition surface at the corner sections.