Double-double: the future of laminates

Double-double laminates in 4-ply [±A/±B] is replacing legacy Quad in 8- or 10-plies of 0, ±45, 90 because DD can be repeatedly stacked to be homogenized laminates.  Complexities of Quad such as mid-plane symmetry and 10 percent rule no longer apply.  Components can be laid along 1-axis with pre-stacked tape with thin plies with 6X speed.  Stacked DD can be tapered to reduce 50 percent weight over Quad.  Free instructions, books and tools are available.