CB as a function of formation temperature at the line cores, T_1/2,c, for the stellar sample. The stars and their spectral types are labeled in the upper left corner of each subplot, and ordered by effective temperature, from left to right and top to bottom. For most stars, the CB shows a linear trend with T_1/2,c, indicating that lines formed at higher temperatures, i.e., deeper layers of the photosphere where convective motion is stronger, are subject to larger velocity shifts. The individual spectral lines are shown as points and the fitted linear trends are shown as dashed lines.