Building On A Two Value Underpainting

I started by coating the entire canvas in pure black acrylic paint.  (If desired another  color -like umber for example, can be substituted for blac k.) I then used white charcoal to indicate only the lightest areas in the composition, creating my two value 'statement.'

                                                                         

Next I painted over the charcoal with white acrylic gesso.  Nearly the entire story is told with simple shapes and only two values. 

                                                                             

I then palette mixed the home colors and started brushing them in transparently.  The various passages naturally  conform to the light/dark value structure set up  in the previous step.  The light passages stay lighter and the dark passages remain darker.  (If you need help with mixing color see my color mixing tutorial )

I continue to palette mix and apply the paint.  I make final value adjustments and paint in smaller details. I lightened the pavement to create more contrast with the row of cars. 

Easton Detention Center  11x14