A polyethylene article produced from a molten polyethylene polymer, which article has a thickness and - at least one local machine direction corresponding to a direction in which the molten polyethylene polymer flowed within a region in the article when the article was produced, - a corresponding local transverse direction perpendicular to each within the article, - a local normal direction perpendicular to each and corresponding and parallel to a line passing through the thickness of the article, the polyethylene polymer comprises a plurality of lamellae each comprising crystalline polyethylene having a b-axis having - a Herman's orientation index at each local machine direction (F MDL,020), - a Herman's orientation index at each corresponding local transverse direction (F TDL,020), and - a Herman's orientation index at each corresponding local normal direction (F NDL,020), the b-axes of the crystalline polyethylene in the lamella being oriented within the article such that F MDL, 020 > 0, F MDL, 020 > F TDL, 020, and F MDL, 020 > F NDL, 020, wherein the article further comprises a nucleating agent comprising a compound of formula wherein R 1 is OH, halogen, optionally substituted alkyl, optionally substituted alkoxy, and optionally substituted aryl; n is an integer of 0-4; L is a linking group comprising two or more atoms and at least one double bond between two atoms in the linking group; v is an integer of 1-3; R 2 (i) is alkyl, cycloalkyl, aryl or heteroaryl, each optionally substituted, if L is a divalent linking group and v = 1, (ii) is alkanediyl, cycloalkanediyl, arenediyl or heteroarenediyl, each optionally substituted, if L is a trivalent linking group and v = 1, (iii) is alkanediyl, cycloalkanediyl, arenediyl or heteroarenediyl, each optionally substituted, if L is a divalent linking group and v = 2, and (iv) is alkanetriyl, cycloalkanetriyl, arenetriyl or heteroarenetriyl, each optionally substituted, if L is a divalent linking group and v = 3; x is a positive integer; z is a positive integer; M 1 each is a metal cation; y is the valence of the cation; b is zero or a positive integer; Q 1 each is a negatively-charged counter ion, and a is the valence of the negatively-charged counter ion; and v, x, y, z, a and b satisfy the equation ( vx) + ( ab) = yz; wherein, if L is a divalent linking group, v = 1, and R 2 is an optionally substituted cycloalkyl, the cyclic portion of the optionally substituted cycloalkyl comprises not more than two ring structures fused together. - at least one local machine direction corresponding to a direction in which the molten polyethylene polymer flowed within a region in the article when the article was produced, - a corresponding local transverse direction perpendicular to each within the article, - a local normal direction perpendicular to each and corresponding and parallel to a line passing through the thickness of the article, - a Herman's orientation index at each local machine direction (F MDL,020), - a Herman's orientation index at each corresponding local transverse direction (F TDL,020), and - a Herman's orientation index at each corresponding local normal direction (F NDL,020), R 1 is OH, halogen, optionally substituted alkyl, optionally substituted alkoxy, and optionally substituted aryl; n is an integer of 0-4; L is a linking group comprising two or more atoms and at least one double bond between two atoms in the linking group; v is an integer of 1-3; R 2 (i) is alkyl, cycloalkyl, aryl or heteroaryl, each optionally substituted, if L is a divalent linking group and v = 1, (ii) is alkanediyl, cycloalkanediyl, arenediyl or heteroarenediyl, each optionally substituted, if L is a trivalent linking group and v = 1, (iii) is alkanediyl, cycloalkanediyl, arenediyl or heteroarenediyl, each optionally substituted, if L is a divalent linking group and v = 2, and (iv) is alkanetriyl, cycloalkanetriyl, arenetriyl or heteroarenetriyl, each optionally substituted, if L is a divalent linking group and v = 3; (i) is alkyl, cycloalkyl, aryl or heteroaryl, each optionally substituted, if L is a divalent linking group and v = 1, (ii) is alkanediyl, cycloalkanediyl, arenediyl or heteroarenediyl, each optionally substituted, if L is a trivalent linking group and v = 1, (iii) is alkanediyl, cycloalkanediyl, arenediyl or heteroarenediyl, each optionally substituted, if L is a divalent linking group and v = 2, and (iv) is alkanetriyl, cycloalkanetriyl, arenetriyl or heteroarenetriyl, each optionally substituted, if L is a divalent linking group and v = 3; x is a positive integer; z is a positive integer; M 1 each is a metal cation; y is the valence of the cation; b is zero or a positive integer; Q 1 each is a negatively-charged counter ion, and a is the valence of the negatively-charged counter ion; and v, x, y, z, a and b satisfy the equation ( vx) + ( ab) = yz;