The illustration above was performed using colored pencils, chalks, pastels, a little of markers and very small gouache retouching; its original size could ensure a good photographic reproduction, and made easier to develop the basic drawing as its scale was 1:1.

Technical illustration is a part of my activity I like very much; nowadays such works are hardly ever required, as a good rendering usually comes as a byproduct of 3D CAD: however, my experience as an illustrator, even with a computer, make me think that the best results in computer graphic can be obtained in three passages: design in a CAD program, rendering in a sophisticated modeler capable of fine photorealistic quality, and a last step of careful retouching in an image-processing program, to add the vitality of brilliant edges and similar, which are often missing as well as in an airbrush illustration before the last brush strokes in gouache. The working times are not so different.