Fractional linear polarization profiles, Q/I (upper panels) and U/I (lower panels), for the core and near-wing region of the K line, for a line of sight with μ = 0.1. The curves represent emergent profiles for syntheses considering a uniform and horizontal magnetic field with different strengths, indicated in the legend. Results for B = 0 − 10 G are shown in the left panels, whereas results for B = 10 − 100 G are shown in the right ones. The B = 10 G case is represented in all the panels as a solid orange curve in order to allow for comparison. Notice that the ordinate scale is not the same for all panels. The reference direction for positive Stokes Q is the parallel to the nearest limb.