A transaction card having a card periphery defined by a plurality of sides, including first and second parallel short sides (104, 106) and first and second parallel long sides (102, 108), the short sides being shorter than the long sides, the card comprising: a metal layer having a front surface and a back surface; and an opening in the metal layer sized to accommodate a transponder chip module, the opening having a first edge being parallel and relatively closest to the first short side of the card periphery, a second edge being parallel and relatively closest to the first long side of the care periphery, and a third edge parallel and relatively closest to the second long side of the card periphery, the first edge being relatively closer to the short side of the card periphery than the second edge is to the long side of the card periphery, and the second edge being relatively closer to the first long side of the card periphery than the third edge is to the second long side of the card periphery, the edges of the opening defining corners (123, 125), and a discontinuity in the metal layer comprising a gap in the metal layer extending from the front surface to the back surface, the discontinuity defining a path from an origin at the card periphery and terminating at a terminus in the opening, wherein one of the terminus or the origin is located relatively closer to a line defined by the first long side of the card periphery than the other, and the path has a length greater than a shortest distance from the terminus to the side of the card periphery containing the origin, wherein the short side of the card periphery has a rectangular region having an edge which is coextensive with the first edge of the opening, wherein the rectangular region extends from the edge to the first short side of the card periphery, characterized in that the origin is located on the card periphery outside the rectangular region. a metal layer having a front surface and a back surface; and an opening in the metal layer sized to accommodate a transponder chip module, the opening having a first edge being parallel and relatively closest to the first short side of the card periphery, a second edge being parallel and relatively closest to the first long side of the care periphery, and a third edge parallel and relatively closest to the second long side of the card periphery, the first edge being relatively closer to the short side of the card periphery than the second edge is to the long side of the card periphery, and the second edge being relatively closer to the first long side of the card periphery than the third edge is to the second long side of the card periphery, the edges of the opening defining corners (123, 125), and a discontinuity in the metal layer comprising a gap in the metal layer extending from the front surface to the back surface, the discontinuity defining a path from an origin at the card periphery and terminating at a terminus in the opening, wherein one of the terminus or the origin is located relatively closer to a line defined by the first long side of the card periphery than the other, and the path has a length greater than a shortest distance from the terminus to the side of the card periphery containing the origin, wherein the short side of the card periphery has a rectangular region having an edge which is coextensive with the first edge of the opening, wherein the rectangular region extends from the edge to the first short side of the card periphery, characterized in that the origin is located on the card periphery outside the rectangular region.