Most of the time I use the gouache materials with here and there pencil for accents.

It is very much a 'à la prima' technique.

I can make the works more vivid in the detailing by using other ways of giving structure or applying the paint.

In case of black and white, (often used in model sketches) I sometimes mix gouache with black ink.

In this way, grey tones can have a special 'extra color effect'.