Mg ii k line profiles of the normally emergent radiation from slabs with D = 200 km. The three sets of curves, increasing in their intensity, correspond to three gas pressures p = 0.01, 0.1, and 0.5 dyne cm^-2. The gray scale corresponds to three temperatures: T = 6000 K (black), 8000 K (dark gray), and 10 000 K (light gray). Only one half of the symmetrical profiles is displayed.