Blank corrections in polarization measurements with single beam spectrofluorometers are straightforward and permit characterization of polarization spectra of samples having quantum yields of less than 0.01. Few samples require no such correction. Problems in determining what is a suitable blank are discussed. Such blanks have unfortunately been ignored in many studies, and dual phototube instruments have been advocated in which it is difficult to apply such corrections. G, the grating correction factor, is shown to vary sharply with emission wavelength, in contrast to other reports, but is independent of slit width. Therefore, a calibration curve of G vs. emission wavelength may be obtained for a given instrument, thus avoiding the need to determine G for each sample.