A system for fabricating a three-dimensional article comprising: a powder dispenser for sequentially dispensing individual layers of powder ; a fusing apparatus for generating and scanning a plurality of energy beams including a first beam and a second beam to selectively melt the layers of powder ; and a controller configured to: operate the powder dispenser and the fusing apparatus to form a sequence of r selectively fused layers of powder in which r is at least 3, the layers individually including a composite hatch area, the composite hatch area includes a first hatch area defined by the first energy beam and a second hatch area defined by the second energy beam, the first and second hatch areas overlap along a seam with a transverse overlap distance (x), a lateral location of the seam varying by layer, for the sequence of r layers the seam varies in lateral location over a zone having a lateral width of v and in which no two layers in the sequence have a transverse distance between seams of less than u in which u is at least equal to two times the transverse overlap distance (x), wherein the controller is further configured to repeat the sequence , characterized in that an orientation of the seam is rotated about a vertical axis Z perpendicular to the traverse axis from one sequence to the next. a powder dispenser for sequentially dispensing individual layers of powder ; a fusing apparatus for generating and scanning a plurality of energy beams including a first beam and a second beam to selectively melt the layers of powder ; and a controller configured to: operate the powder dispenser and the fusing apparatus to form a sequence of r selectively fused layers of powder in which r is at least 3, the layers individually including a composite hatch area, the composite hatch area includes a first hatch area defined by the first energy beam and a second hatch area defined by the second energy beam, the first and second hatch areas overlap along a seam with a transverse overlap distance (x), a lateral location of the seam varying by layer, for the sequence of r layers the seam varies in lateral location over a zone having a lateral width of v and in which no two layers in the sequence have a transverse distance between seams of less than u in which u is at least equal to two times the transverse overlap distance (x), wherein the controller is further configured to repeat the sequence , characterized in that an orientation of the seam is rotated about a vertical axis Z perpendicular to the traverse axis from one sequence to the next. operate the powder dispenser and the fusing apparatus to form a sequence of r selectively fused layers of powder in which r is at least 3, the layers individually including a composite hatch area, the composite hatch area includes a first hatch area defined by the first energy beam and a second hatch area defined by the second energy beam, the first and second hatch areas overlap along a seam with a transverse overlap distance (x), a lateral location of the seam varying by layer, for the sequence of r layers the seam varies in lateral location over a zone having a lateral width of v and in which no two layers in the sequence have a transverse distance between seams of less than u in which u is at least equal to two times the transverse overlap distance (x), wherein the controller is further configured to repeat the sequence , characterized in that an orientation of the seam is rotated about a vertical axis Z perpendicular to the traverse axis from one sequence to the next. <EOS>