Now, using a no. 8 hog hair brush and thin paint start colouring in the sketch. I started at the top left. This area of the forest is three miles from Peters Pool (my mate lives there) so I used a large pile of "atmosphere" into which I added about half the amount of "shadow". As I worked forward down the painting I added appropriate amounts of shadow to the atmosphere until I got to the bottom by which time I was using pure shadow. I used a touch of orange to paint the tree in the middle and sap green for the grass in the centre. Work fast and loose and don't worry because most of what has been done will be covered up. The whole process took me about 20 minutes. Now I can compare my work with the real thing and decide on matters like composition etc.