Masterclass Oil Paint Technique by Poen de Wijs

A SHORT MANUAL
THE PREPARATION OF THE CANVAS

A ready-made canvas is usable, but for the use with fine details, one or two 

extra ground layers are likely to be required. Undiluted GESSO-primer is spread using a rubber squeegee (of which the corners are cut off). After drying, this prime ground has to be sandpapered.

THE FIRST LAYER IS FOR THE CREATION OF SHAPE
After the preparation of a painting, in which the idea and sketch, possibly photography and study, have led to a final composition. A working drawing with the size of the canvas or panel is made. The purpose of this is working 

drawing is to capture the pure form of the various components. The outlines can be made by pressing with greaseproof carbon paper (see the book on drawing).

THE SECOND LAYER IS FOR LIGHT AND DARK
The entire presentation is being painted with high white and warm dark grey (not black), in great light and dark sides. Since the outlines were already determined, and the color is to come, full attention is focused on the contrast of light and dark, expressed in greyscale. For a short drying time and a smooth paint a little medium is required.

GRISAILLE
The result of this layer is a complete representation, without any details, all in grey. This is called ‘grisaille’. Formerly, grisaille was often made in tempera. Nowadays acrylics can be used. Both paints are excellent, and overpaintable with oil. 

In my own work I choose diluted acrylic paint, which creates a smooth, soft and blurry grisaille. As indicated, the grisaille may be painted in grey/white /dark grey. I, however, choose a different way: I build up the grisaille from two opposite (so-called ‘complementary’) colors: cobalt blue and Venetian
(= English) red, by which no mixed grey, but an optically mixed grey occurs. Optical mixing, obtained by not mixing colors, but by applying them on top of each other, makes the grisaille diverse and lively.

THE INTERMEDIATE LAYER
After the acrylic underpainting, an intermediate layer is needed. This, as a transition between acrylics and oil and to soften the underpainting. Turpentine, mixed with LIQUIN (2:1) and a little oil, gives a mixture that makes smears and rubs well with a cloth. Over a grey/white /black grisaille 

sufficient raw umber or ochre is mixed off. On a cobalt blue/Venetian Red underpainting a dirty greenish layer is recommended. When the underpainting is considerably darkened a small amount of white can be blended.

FUNCTIONS OF THE THIRD LAYER
Through the working of light and dark, the gentle setting of the colour and  indicating parts of the details. This laborious layer will be painted, with a bit more medium in the paint, semi-transparent, part by part. First, a semi-transparent soft colour will be rubbed over a portion of the grisaille, so that a shadowy image arises. Because of the semi-transparent nature of the paint, light and dark colour will shimmer through.

 

Then in the wet colour the light areas with light tones and shadows with dark shades are worked through. Both light and dark shades are usually derived from the colour used. Each part of the presentation will be processed in this manner. The result of this operation, which requires considerable time, is a well-thought through presentation, cool, soft, pastel-like of expression.

 

THE FOURTH LAYER IS FOR COLOR
The final color is determined by the application of a transparent layer (the so-called ‘glazing’). The colors, without the addition of white, will be mixed with lots of medium, and will be thinly painted over parts of the presentation like colored glass filters. This glazing requires much experience. The principle of optical mixing is simple. For example, transparent blue over a yellow underlayer gives a green outcome. But because usually colors are already mixtures, the outcome is very difficult to predict. Multiple transparent layers

 form a complicated amalgamation of optical mixing. To include light, shadows and details in the wet transparent layer semi-transparent and opaque colors can still be applied. The glazing can be done very locally or over larger parts of the presentation. Two, three, four or more layers are possible. When the game of these layers is well played, the painting comes slowly to a level where the light areas express a radiant light, and the dark areas are saturated. Their colors are rich in gradation and mysterious in mixing.