Comparison of the synthetic spectral energy distributions of Wd1-27 and -30a derived from model-atmosphere analysis to observations (Sect. 4). The band-passes of the filters are delineated by green dashed lines, photometry with red diamonds and the (reddened) synthetic spectra by the solid black line. Errors on photometric data are smaller than the symbol sizes. Reddening parameters and resultant bolometric luminosity are also indicated.