The texture of ordered phases of block copolymer melts and gels is highly sensitive to shear. In the body-centered-cubic phase of a block copolymer system [polystyrene-poly(ethylene butylene)-polystyrene] mixed with oil, we show how a given textures can be controlled with the application of a specific shear rate and amplitude. The low-amplitude shear texture is dominated by [001] planes perpendicular to the shear gradient and by the [110] axis parallel to the flow direction, that is, the {001}/[110] slip system. Detailed crystallographic studies show that both intermediate-amplitude oscillatory shear and large-amplitude oscillatory shear lead to twin structures with (1121 planes sharing neighboring twins and [111] axes parallel to the shear flow. At an intermediate shear amplitude, the ve shear plane, defined by the shear flow direction (v) and shear vorticity direction (e), is parallel to the {112} twin planes. At a high shear amplitude, the orientation is rotated 90degrees, and this makes the ve shear plane parallel to the 11101 crystallographic planes. The crystalline slip system is accordingly ({11 (2) over bar}/[111] + {(11) over bar2}/[111]) under intermediate-amplitude shear and (1 (1) over bar0)/[111] + {(1) over bar 10}/[111]) under large-amplitude shear. (C) 2004 Wiley Periodicals, Inc.