We have predicted and observed in a nematic phase of a liquid crystal (MBBA) a new kind of instability formed of rolls perpendicular to the Williams domains. In contrast to the latter, the spatial period of this new instability is a function of the voltage. This instability is due to the fact that the director points out of the substrate plane.

We discuss the alignment of nematics and smectics on substrates where an obliquely evaporated thin film has been previously deposited. In the planar samples, the surface anchoring energy is substantially larger than with the traditional rubbing technique. We can also uniformly align the liquid crystals obliquely, in particular by coating the evaporated film by a surfactant.