Balmer-decrement based estimated values, c′, for the logarithmic extinction at Hβ for PNe in the LMC, M33, and M94, as a function of [O iii] λ5007 absolute magnitude. These values are slightly overestimated, since Hα is partially contaminated by emission from [N ii]. Spectroscopically derived values of c (without the [N ii] adjustment) in the Magellanic Cloud are shown as gray circles. Note the general agreement between galaxies; there is no evidence for an extinction dependence on metallicity, nor is there any significant trend with absolute magnitude.