From the Winter 2015 issue of RA Magazine, issued quarterly to Friends of the RA.

Why did you make this painting?

In the past year I have become hooked on the squares in Chelsea. I went out walking near my home with an artist friend, Peter Brown, who was already painting squares, and I started to really notice them. This subject – Redcliffe Square – is three minutes from my studio. I knew I had to paint it in winter – summer is green and fat, you can’t see the structure of things. In winter you can see everything – the sequences of contrasts, from the figures sitting on the bench to the path to the church, for example. I painted this picture in the afternoon when everything was set against the winter light.

What was the starting point?

One of the first key decisions was where that main tree would be. I established it about a third of the way across the canvas. Then I thought, “I want to get this foreground where the grass is wearing out, as it’s wintertime.” I also wanted a certain amount of sky because it was a warm afternoon. These were aesthetic decisions but the starting point is also always an intuitive thing. I moved my viewpoint until the relationship between all these elements gave me that sensation of being touched – as art is about being touched.

What techniques did you use?

I was interested in the contre-jour effect, when one paints facing into the light. My natural way of working is through tone: the sky against the tones of the church and the trees, and the figures on the bench against the buildings on the right – these were the relationships that excited me. I covered the canvas in a halftone mix of ultramarine, burnt sienna oils and an oil-based Dulux white undercoat, so that the foreground marks of the grass, for example, could be made in relation to that halftone. I am always looking at tone, so it’s a process of continuous adjustment.

Were there any major challenges?

To catch the light and its changing effects, you’ve got to paint quickly. Practice makes you fast. At the same time it is a constant struggle – you are constantly questioning, sometimes questioning your own ability. This picture was completed in a couple of two-hour sessions. I did the entire painting on the spot.

At what point did you feel the painting was going to work?

When I realised I couldn’t do what I was trying to do! We paint our best things when we paint completely intuitively – you can’t shed what you’ve already learned but somehow you’ve got to, to let go of all that experience, to lose control.

How did you know when it was finished?

It’s done when it gives you back the sensation that made you first think, “Oh I’ve got to paint that.” The last marks were the figures on the bench because they finally gave the contrast I needed with the church and the little group of bare trees behind the bench in the background.

How do you feel about the painting now?

The sensation of light is there, and the sensation of Redcliffe Square on this day. I want to paint the square again. It has so many contrasts – between tones, colours, between nature and city.

Ken Howard RA: From London to Venice is at Richard Green, London 020 7499 3748, 13 Jan–6 Feb 2016.