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.