Lay the skull stencil on your airbrush drawing board. Carefully spray the stencil using Hansa pro-color Black thinned with water. The holes for the eyes and nose will appear a little darker in shade.
This is the intermediate stage.
Add the highlights and shadows completely with a free-hand technique, using highly transparent black. You will be able to rub and scratch the paint layer on the surface only if it has been thinned with plenty of water. Depending on the type of painting surface and the thickness of the paint, you can rub areas to make them light, e.g. if they have become too dark, or use white (opaque or transparent as you wish) to lighten them.
Use black paint which you have mixed with a lower proportion of water for the next layer of paint. Add more detail to the skull structure. Work very closely to the painting surface when adding details so that you do not have so much overspray.
If you are painting on drawing board, you can use an eraser pencil or electric eraser to create the light areas on the horns, teeth, jaws and the entire skull structure.
Using an electric eraser allows you to set precise highlights, making areas lighter again.
The previously black and white picture now begins to show color and structure. Mix a couple of drops of HANSA pro-color Umbra, HANSA pro-color Lemon Yellow and a large quantity of water to make a transparent liquid. Soak up the paint in a loosely wadded paper towel and carefully dab on the brownish paint. Turn the towel repeatedly so that it does not look like a stamped structure.
Continue spraying with a transparent brown/beige shade. This gives color to the skull. As you spray over the painting, make sure that the skull does not become too dark overall. Spray several layers of paint in the shadow areas and only a small amount of paint in the light-colored areas of the skull.
Use a slightly darker, transparent brown shade, e.g. Hansa pro-color Umbra mixed with a small amount of water, for the darker places on the skull.
Use aids such as electric erasers, eraser pencils or brushes to add additional details such as points of light and structures.
Here is the finished picture. Spray the background to create an intimation of a stone structure. Use the "Skull Set" to realise your own pictures on different surfaces.
The "Skull Set" also contains the frontal view of the skull with horns. You can realise this motif using the techniques described above. For example, use the different sizes of the stencil for additional background patterns. Have fun experimenting!