"Very simply, WhiBal™ combines all the best features of all available Gray cards and meets or exceeds their technical performance in a unique package that can be used conveniently in all your shooting situations. In addition, WhiBal™ provides convenient neutral White and Black reference areas for setting dynamic range in your digital capture using the Black and White Eyedroppers available within RAWShooter and other RAW conversion software, Photoshop™ and most other editing software." To learn more click here.
BTW, I do not work for, get paid by or own stock in WhiBal, wish I did.