As a precursor to calculating the transfer of radiation through a model stellar photosphere, we now look at the continuous absorption coefficient. The wavelength dependence of the continuous absorption coefficient shapes the continuous spectrum emitted by the star: more absorption, less light. The strength of spectral lines also depends on the continuous absorption; more continuous absorption means a thinner photosphere with fewer atoms to make spectral lines. Consequently, we must know kν in order to match model-computed spectra to real stellar spectra. However, before we can compute the theoretical spectrum, we need to compute the model on which it is based, and that too can require kν. Specifically, if we invoke radiative equilibrium to find T(T0), then kν is needed from the very beginning. Furthermore, it then becomes particularly important to know kν in those spectral regions carrying most of the flux. In hot stars, this means the ultraviolet region, in cool stars, the infrared region. We escape this step if T(T0) is determined empirically, say by scaling the solar temperature distribution; the main need for kν reverts to the computation of the spectrum. Since scaled temperature distributions are emphasized in this book, kν in the visible window is the main focus of this chapter.