Complete Artist’s Manual: The Definitive Guide to Materials and Techniques for Painting and Drawing. Simon Jennings
| MIXING OIL COLOURS | Oil paint is expensive, but do not be mean with it. Always squeeze the paint out in generous mounds, or you will be constantly unscrewing tube caps and mixing up fresh batches of paint, which can become a chore. Any paint that is left over at the end of the session can always be reused in one way or another. |
Keep colours clean
Try to avoid using more than two or three colours in any one mixture. Any more than this, and the colours become lifeless and muddy. Always have a large jar of turpentine and a rag nearby, so that when you have finished with a particular colour you can clean the brush or palette knife thoroughly and not contaminate the next colour.
Mixing methods
When mixing oil paints on the palette, use either a brush or a palette knife. A knife is preferable for mixing large quantities of paint, and it will certainly save a lot of wear and tear on your brushes. When working fast and mixing small quantities of colour, however, a brush is more convenient. Old, worn brushes are useful for this purpose – never mix paint with sable brushes, as it quickly ruins them.
Adding diluents
Mediums and diluents should be added to paint gradually, and in small amounts. Including an excess of thinning agent may result in an underbound paint film that is prone to flaking.
Mixing paint
Fully mixing two colours produces a solid third colour; partly mixing them allows the two original colours to still be part of the mixture.
Reusing oil colour
Scrape paint off the palette with a knife and store in an airtight container for use next time round. Even ‘palette mud’ (the dull colour left when many colours have been mixed) can be useful – thin it down with turpentine and use it for tinting canvases and boards. Paint which has been exposed on the palette for long periods will have begun to oxidize, and is therefore not stable enough for use. If the paint feels gummy or it requires a lot of thinners to make it workable, then it should be discarded.
Palette-knife method
A palette knife is convenient for mixing large amounts of paint and avoids damaging your brushes. Use a scoop-and-slide action to mix the colours thoroughly.
Brush method
When mixing paint with a brush, use gentle sweeping and rotary motions in order to minimize excessive wear and tear on the bristles.
SEE ALSO
| MAKING OIL PAINTS | Until the nineteenth century, oil paints were made by hand in the artist’s own studio. However, since then, artists’ colourmen have perfected the way in which oil paints are manufactured to such a degree that, in terms of quality and handling properties, they are now considered far superior to those of hand-ground paints. But home preparation of oil colours is a quite straightforward process, and it allows the artist to have complete control over the ingredients in the paint. |
Home preparation
It is much cheaper to buy the raw materials than the ready-made tube colours, and the larger art-supply stores carry a wide range of raw pigments from which you can mix colours to your specific requirements. Finally, there is undoubtedly a lot of satisfaction and pleasure to be gained from working with colours that you have prepared yourself.
Method
(1) Mix the pigment and oil to a stiff paste with a palette knife.
Spoon a handful of powdered pigment onto a glass slab, and make a well in it. Pour in a spoonful of oil, and mix to a stiff paste with a palette knife (1). Ensure that all the pigment is thoroughly wetted, but do try to use the minimum of oil to produce the stiffest workable paste. Too much oil may result in yellowing and wrinkling of the paint film.
Mulling
(2) Grind the pigment and oil mixture with a smooth figure-of-eight motion.
Grind the pigment and oil mixture on the slab with a glass muller, using reasonable pressure and a continuous smooth, circular or figure-of-eight motion (2). Your weight should be well balanced over the muller. The objective is to disperse the pigment particles evenly through the binder and to achieve a smooth, glossy paint, free from grittiness. Be warned – mulling paint to the right consistency can take up to an hour, depending on the pigment! It is best to mull a small amount of pigment at a time, moving each freshly mulled batch to the edge of the slab.
The resulting paint should be stiff enough to be workable while containing the minimum of oil. If the paint doesn’t ‘peak’ when lifted with the tip of a palette knife, it probably contains too much oil; add more pigment and mull again.
Using lightweight pigments
Those pigments that are fluffy or flyaway, due to their light weight and fine particle size (for instance, alizarin and the quinacridones), need wetting before they can be ground with oil. Saturate the pigment with white spirit until all the powder is wet, then leave to dry out a little on absorbent paper before mixing to a paste with oil.
Filling the tubes
(3) Pack the freshly mulled paint in empty collapsible tubes. First loosen the cap of the tube a little so that air can escape. Hold the tube upright and fill from the open end with a palette knife.
The freshly mulled handmade paint can be stored in empty collapsible tubes which are obtainable from major art-supply stores. As a guide, roughly 300g (10.6oz) of paint should fill a 150ml (5 US fl oz) tube. Loosen the cap of the tube a little so that air can escape as you fill it. Hold the tube upright and scoop the paint into the open end, using a palette knife (3). Fill the tube to within about 25mm (1in) of the open end, occasionally tapping the tube on the table to settle the pigment and disperse any air bubbles.
Pinch the tube 30–40mm (1¼–½in) from the end to expel any air. Wipe the tube clean, then make a double fold