What's the best, fastest, and easiest way to get GREAT color out of your digital camera? The BalanceSmarter popup grey / white card available now in 3 sizes.
We have a whole website filled with info on how to use this great tool and plenty of free video tuutorials for you right here.
What size BalanceSmarter is right for you?  Well, if you use a lot of wide angle lenses, you may benefit from the 20 version, if you work mostly in the studio go with the 30 inch version, and if you need maximum speed and portability, try out the 12 inch version.
This is the official product recommended by Will Crockett in his videos and seminars for great custom white balance on Canon, Nikon, Fuji and Sony digital cameras.