Last Sunday I was monopolising the cafe table with the best view on Avenue de l’Opéra.  These are the prep studies in preparation for my main painting below. I don’t always bother with these (there are only so many coffees you can drink in one sitting).  But they are extremely useful for working out what is going on under the surface before you start.

What a mess! These are the bare bones of the painting – the main perspective lines (which I think most people get right) and the main colour and tone changes (which are easy to overlook).

Watercolour washes look most alive when there is a change of hue or tone across a shape. Look closely and almost every “flat” surface you see gradually changes colour. This effect is most marked when you have strong cast shadows, as the edge of a cast shadow will look much bluer because it is next to yellow sunlight.  Ruskin talks about this in his section on “local colour” in The Elements of Drawing (Dover Art Instruction, 2012) – and suggests that you should look through a small window in a piece of white card to make it easier to truly judge a colour in isolation.

Similarly, buildings against the sky will often have a much darker tone against the sky than mid-way down the facade.

This is the “full” prep study.  The role of this study is to decide the main tonal relationships between the far side of the street, the Opéra Garnier in the background, the near buildings and the people and streetlights in the foreground.

I got a bit carried away with this one – four quick washes would have got the job done. But the sun was shining, I was trying out a new drawing pen, and with a quick prep study I often feel nothing can go wrong and if it does, who cares?

After all that, I didn’t have much time to do more than get my drawing down for the main painting and lay in a first couple of washes.  By then the sun had moved round so the colours and tones were changing – definitely time for lunch.

I finished the painting using my reference studies later in the afternoon in my studio (ok, ok – on my dining table).