• Set your digital camera for the correct light source type or do a custom colour balance.

This is done by Taking an image of shooting either a neutral black, grey or white image (make sure you include only the card in the frame) setting the camera white balance mode to custom and then selecting the image you have just taken and setting the white balance.

With film you will have to use the appropriate film type- daylight or tungsten - or use a 80B conversion filter for tungsten lights.
GC3
Three matt patches on cardboard: 90% white, 18% grey and 1% black (velvet).
Size: 60x203 mm.