.... and ? which one is the best ... this graphic tells me nothing
When the goal is to have a reference target that reflects light uniformly across the spectrum, the Babelcolor White Reference does a better job. The WhiBal doesn't do bad either, although it lacks a bit of deep blue and near UV remission, so a white balance may turn out slightly on the cool side because the card looks ever so slightly warm (assuming the lightsource and/or ambient light contain a significant proportion of these short wavelengths to begin with). Both targets do not seem to suffer from fluorescence effects.
Cheers,
Bart
