Understanding Colour: Mixing Greys - Anachromatic Scale

This exercise required the mixing of black into white paint to create a progressively darkening scale with the final step being black directly from the tube.

On my first couple of attempts at this, some of the tonal values in the mid range were very similar to each other. I gradually came to realise that it was not sufficient to mix the same amount of black into the mixture each time to make a stepwise tonal gradation. As the tone got darker, a progressively larger volume of black paint needed to be added to make and appreciable difference to the value.

My final attempt has nine steps although step 7 and 8 are quite similar compared to the the rest of the steps so in retrospect it probably should have stayed as an 8 step scale.  I then took scraps of paper painted with a mid-range neutral great and placed them at each end of the scale.  The result is that the grey placed adjacent to the white end of the scale appears relatively darker in tone and the grey placed adjacent to black appears relatively lighter. 

The neutral grey was then used as a base colour for the subsequent colour mixing exercises.