Acrylic with some airbrush on canvas panel, circa 1976.

Portraits painted in acrylic enjoy much of the look of an oil painting since both are opaque media that have a thick consistency. The one drawback of acrylic compared to oil is the quick drying time. This provides very little time to blend colours and values right on the canvas, a technique needed to produce the gradual shading found in facial features. This drawback is even more of an issue where the subject is a child, since their skin is quite smooth and delicate shading is needed.

The airbrush comes in very handy to solve this problem. Its main feature is the ability to apply pigment in very smooth gradations. Using an airbrush with a thicker, opaque medium such as acrylic is a problem though. The paint must be thinned, otherwise it can't be sprayed by the airbrush. But if it's too thin, it becomes too transparent and it runs easily. If it's too thick, it will gum up the airbrush very quickly and the spray is not fine. Getting the paint to the right consistency is a matter of trial and error. Even so, the airbrush tip must be cleaned annoyingly often during the work.