Having a "Grey Card" reference is the best assurance that the digital pictures that you capture will have the ability to be properly White Balanced. Only with a proper White Balance can you be ensured of proper and accurate color, regardless of lighting conditions. Unlike your eyes, a digital camera does not automatically see whites as white. It sees the color of the light reflected from it, hence blue-ish in Daylight and Orange-ish in incandescent lighting. By photographing a Gray Card reference for each lighting situation that you are in, you are assured of being able to achieve a proper White Balance for all of your pictures. The Gray Card reference picture can be used with today's software to balance the color casts that various lighting conditions produce with all digital cameras. The best method to properly White Balance your digital pictures is by using a Gray Card properly and shooting RAW. RAW Conversion Software such as Adobe Camera Raw and Lightroom can then perfectly adjust all the captures that were shot under the same lighting conditions. And the beauty of the WhiBal® is that it is small enough to fit in your pocket or around your neck, so that it will be used on a regular basis, as above. Remember that the most accurate Gray Card is useless if it sits in your camera bag.