13- Once you have finished painting the part (C) of the banana, you will remove the transparent film of all the part (D) which will be also laid on the support paper of the transparent film. Then erase all the visible pencil marks.

14- Now, you must replace carefully in its position the film of the part (C) in order to mask the banana. (no need to replace the films of the brown marks)

15- Spray with the same paint the part (D) as in paragraph 12, following carefully the curve of the banana. This part (D) will not be brighter than the part (C).

16- When you have finished with spraying the yellow color in the part (D), you will pour 4 drops of water, 1 drop of yellow Ochre paint and 1 drop of Raw Sienna paint to make the Yellow Ochre darker.

17- The yellow color which has now become darker will be sprayed all along the lower part (D) and a little bit all long the upper part. A strip in the middle of this part (D) will not be sprayed and will therefore remain in yellow Ochre color in order to give the shape of the banana.
Spray continuously by passing several times over the same place always following the curve of the banana shape until you get the correct dark yellow color. (The lower pat (D) will have to be darker than the rest of the banana.)

18- Remove again the film from the part (C), it is not necessary to mask again the part (D) then using the same dark color paint, you will spray a light shadow right at the two extremity of the banana. You will also draw some very light dark strip of shadow all along the part (C) following the curve shape of the banana. This will give a stringy aspect to the banana skin.

19- Phew! You have now finished with the banana.

20- But you still have to paint the background.

Remove the transparent film (B) but leave the film of the frame (A). Then, erase all the remaining pencil drawing still visible.

21- Replace on the banana the films (C and D) exactly at their right place. Do the same with the 10 brown marks and the extremity of the banana.
At this stage, the banana must be completely covered with the film as on the picture. (Please check)

22- To achieve the background, you will pour in the empty container of your airbrush 6 drops of water, 2 drops of
Turtle Dove grey paint, and 1 drop of Light blue paint.
Start spraying from left to right and a little past the edges of the paper starting from the upper part of the drawing. (You must hold the airbrush with one hand). You will spray without stopping progressively down the page then up again in the same way and several times until you obtain the expected color. 
In order to obtain an evenly plain color for the background, it is recommended to spray lightly with several passes (after each pass the color will darken) rather than one or two passes of thick layer of spray)

23- The moment of truth has now come!
The last things to do now are to remove thoroughly the transparent film from the banana (C and D) and from the outside frame (A) helping yourself with the cutter and…to admire your achievement.

24- In order to protect the paint you can spray 2 or 3 layer of clear varnish for acrylic paint.

My airbrush book
in French