Oil paints are made mixing pigments with oils or resins and diluting them with spirits. They date back to ancient times, but it wasn�t until the Flemish painters of the 15th century began to use them systematically that painting in oils became consolidated as a technique.

Techniques
There are two basic ways of painting in oils:
- Alla prima: Also known as direct painting or wet-on-wet, in which the paint is applied to the canvas in a rapid, free style. The painting will usually be finished in just one session, so opaque colours which obscure what is underneath them are generally used. This is the technique most commonly used by the great landscape artists, such as Constable or Caravaggio.

- Indirect painting: The work is painstakingly planned and is carried out slowly using successive layers of paint: sketch, laying in (the application of some basic colours and shades), colours� This method was used by such prestigious artists as Van Eyck, Rubens and Turner.

Materials

The first thing you need is somewhere to paint and the necessary materials to paint with:�

- Place: It is a good idea to set up a room or some space in the house to paint in. With regard to light, ideally there should be natural daylight coming through a north facing window, so as not to get direct sunlight.

- Easel: There are several types of easels on the market, in various designs and made of different materials. The important thing is that it should be sturdy so it won�t wobble while you are working and cause you to make mistakes.

- Painting case: It is advisable to buy an empty one and fill it up according to your preferences and needs: palette, paints, brushes, spatulas, rags, sketchbook, pencils, charcoal.

- Palette: Choose one of the right size, weight and balance. A heavy one will cause tiredness and even pain in your wrist. It should be a light wood colour or white, with a smooth, easy to clean surface.

- Brushes: There is a wide range of brushes, both in terms of bristle or hair type and size. You should opt for a small but varied range of quality, precision brushes.

Creative process
Once you have gathered all the materials together, you are ready to start the real creative process of painting in oils. The basic steps are:

1) Before you start painting you need to fix your canvas on a wooden stretcher and adjust the tension to your liking. Canvasses for oil painting are most commonly made of linen or hemp.

2) Next you have to prepare the canvas to receive paint. This process is called priming and is carried out in two stages: firstly the surface is made impervious by brushing on a coat of size, and then a mixture of hide glue, zinc oxide and calcium carbonate. Not all the canvas should primed since it would lose elasticity and might crack. After priming the canvas should be white.

3) Mixing and diluting the colours, using oils, resins and spirits.

4) Now comes the really creative part, when your work of art begins to take shape as you apply paints to your canvas. At this point it is very important to study colour theory, which will allow you to control every colour�s behaviour, and thus exploit their expressive potential to the full. This involves studying colour mixing techniques, discovering the many shades and tones of each colour or hue, learning about families of colours etc. Colour theory is a subject which will normally take hours of study, trial and error, and above all, a great deal of patience.

5) For your first attempts at oil painting you should give free rein to your imagination, exploring the wealth of possibilities that the different colours offer, and letting your creative juices flow. Basic oil painting techniques can be incorporated and refined, little by little, as you get more practice.

6) When you have finished painting a canvas, give it a coat of protective varnish.