Transmission spectra for the warm Saturn HAT-P-12b, along with the observational data taken from Sing et al. (2015a). For clarity, a vertical offset has been applied to the various models. The cloud species considered here are Na₂S and KCl only. From top to bottom, the following cases are plotted: a) homogeneous clouds, with a maximum cloud mass fraction of X_max = 3 × 10^-4·Z_Pl per species and a single cloud particle size of 0.08 μm. Iron clouds have been neglected; b) like a), but including iron clouds; c) self-consistent clouds using the Ackerman & Marley (2001) model with f_sed = 1; d) like c), but using f_sed = 0.01; e) clear, fiducial atmospheric model. The colored bars at the bottom of the plot show the spectral range of the various JWST instrument modes. The dotted horizontal lines denote the pressure levels being probed by the transit spectra with the pressure values indicated on the right of the plot.