Radial profiles of different emission-line properties, stacked by morphological type. Each point represents the median value of the unmasked profiles at a given galactocentric distance, in bins of 0.3 HLR. Elliptical and lenticular galaxies are not represented given that most of the values of their profiles are masked. The shaded area marks the uncertainty, calculated as the standard deviation divided by the square root of the number of points in each R/HLR bin.