The determination of the texture of the order parameter is important for understanding many experiments in superfluid 3He. In addition to reviewing the theory of textures in superfluid 3He-B we give several new results, in particular on the surface parameters in the Ginzburg-Landau region and bulk parameters at arbitrary temperature. Special attention is paid to separate the results that are valid at all temperatures from those which are limited to the Ginzburg-Landau region. We study the validity of a trivial strong-coupling model, where the energy gap of the weak-coupling theory is scaled by a temperature dependent factor. We compare the theory with several experiments. For some quantities the theory seems to work fine and we extract the dipole-dipole interaction parameter from the measurements.