The potential of printing stiffeners of polylactic acid (PLA) by Fused Deposition Modeling (FDM) on the panels of folding board boxes was investigated in view of reducing the board weight while maintaining the box resistance to vertical compression. Cyclic loading and unloading compression tests were performed under standard (50% RH) and humid (85% RH) environmental conditions on boxes printed with different grid patterns. By only adding 7% in weight of PLA to the whole packaging, the performance was improved by 29% under standard conditions and 60% under humid conditions when the inner surface of box panels was printed with an orthogonal-type grid. A comparison with a higher basis weight folding board suggested that 30% of raw materials could be saved. Results suggested that the grid mainly improved the elastic properties of the panels and could delay the buckling of panels and thus the box collapse. Furthermore, the grid pattern could affect the buckling shape that the panels took.