This photo was taken to show you the painting technique I used to lighten the sky. I squeezed a little white paint (acrylic) directly onto the painting, towards the top left and right. Then I dipped my brush into clean water and started spreading out the paint.
I continued to do this (dip brush in water, spread paint) until the whole sky area was painted. In some places where the paint was too opaque and thick, I lifted a bit off with a clean cloth, then added some more water to make it more of a glaze.
As acrylic dries rapidly, this is a technique that required speed... pause too long and the paint will dry before you've done with it what you want. (If this does happen, don't despair, but paint some blue over the top of the white.)
