Knowing how to make and use this oil medium is probably the greatest secret a painter can learn. It is truly remarkable stuff, and yet it can be made easily by artists with minimal cost and effort. Before I tell you how to make it, I have to extol its virtues, because if you understand and learn to appreciate its potential it will have a profound effect on your paintings. I cannot emphasise this enough. It will allow you to form a glaze to stretch out colour without it ever breaking or failing. It can mix with your paint to form such a delicate and fine layer that the colour reduces to a point where your eye can no longer be sure it’s actually there. Or to put it another way, imagine creating a shadow on the side of a face with burnt umber, which you want it to fade very softly at the edge where it meets normal light. Linseed oil mixed with colour will allow you to fade it in a wonderfully controlled way, without the colour smudging to nothing on the canvas or, as may be the case, onto the dried paint of the cheek below your shadow. It also speeds up the drying of all paint and mediums with which it is used.
What you will need:
- 1 cooking pan, measuring 10 x 7 and about 4 inches deep (25.4cm x 17.8cm and 10.2cm deep)
- 1 glass sheet, slightly bigger than the pan
- 4 pieces of wood – matchsticks are ideal
- _ Litre or _ pint Linseed oil
Take a litre or so of refined linseed oil and pour it in a metal tray. Enamel cooking ones are ideal. Pour enough oil in to create a depth of half an inch (12mm). You will need a glass sheet slightly bigger than the pan to cover it over. Place 4 small pieces of wood (discarded matches are ideal) to act as spacers so the glass sheet is slightly lifted off the cooking pan. This allows the passage of air and keeps most airborne rubbish out, although any errant flies will have to be removed by the butler! Leave it in a window in direct sun light and stir or whisk it every other day for a minute or so, just as you would eggs. This will aerate it, and you will find after 10-15 days it is becoming thicker and more gloopy in texture. The longer you continue the process the thicker the texture will become. The density of the texture is a matter of personal preference. The thicker the viscosity the greater the handling power and it is something you will have to explore until you decide what is best for you.