Summary

Tool for setting your exposure, white balance, white and black point, and contrast right from the start of image editing. Provides accurate correction across shadow and highlight tones. Goes beyond a grey card by letting you set a true black point along with defining your primary light source for accurate white balance correction.

Colors to be used
Upper part --> middle grey (18% to 25% luminance)
Median part --> white
Lower part --> black
Internal part --> black
Support --> black

Cube size is 50x50x50 (mm)
The inner part should be printed with supports that can be easily removed by the hole (large grid)
Once printed, the different parts must be glued together
Support could be mount on a tripod or on it's own base.
On the top there is a place to glue a glass ball or a metal ball from bearing.