I understand from industry publications that much of the skin panels in the 787 are composed of three dimensional woven fabric, rather than uni-directional roving. Hence the finished panels have fibres running perpendicular to each edge and surface which significantly enhances its resistance to transverse cutting or cracking
Most CF is multi-layer uni-directional weave, with the strength coming from the weave directions used. The weight of the part is determined by the amount of layers used, hence specific parts or areas requiring specific strengthening can be re-overlaid with more layers of the same direction weave in the sandwich, whereas less critical areas can be the traditional 3-layer weave.