I don’t know whether you’ve ever noticed it, but colour has a lot of psychological significance; some colours can make you happy and some sad, some heavy and some light. I try to use colours that heighten the feeling of what I want to say. For instance, if I was painting a young girl, I wouldn’t use browns and purples and heavy colours like that; I’d naturally use something that’s light and youthful and airy, happy, perhaps, depending on whether I wanted to make her happy or sad. If I was painting an old man, I wouldn’t use light greens and light blues, things like that. That’s only a very rough basis for psychology of colour.
Quite often I use drawings, particularly in portraits. When I have a portrait commission to do – not a commission necessarily but a portrait – I usually do a lot of drawings. I like to become familiar with the subject, especially the character of the subject and the general feeling of it. I usually throw the drawing away and do the painting from memory. But usually now, with an ordinary subject, I just start straight on the large canvas and work it out from there. Once a picture is started, it sort of paints itself. What I mean is: when you put a brushstroke down, it indicates the next brushstroke to put down and so on, it’s like doing a jigsaw puzzle in which you put one piece in place and you have to find another piece to fit in with it.