Evening and Night: Painting Light

At night, everything you learned during the day flips around. Buildings become dark blocks, the sky glows, and a single window can carry the whole picture. This is exactly where opaque paint shows its strength: you can put light over dark. With watercolour you'd have to painstakingly reserve every light — with acrylic or gouache you paint the night first and cut the lights into it afterwards.

Dark first, light last

Start with a dark underpainting of ultramarine and burnt sienna. Together these two colours make a deep, almost black grey that you can tip in either direction: more ultramarine makes it cool and bluish, more sienna warm and brownish. Because you control the mix yourself, it stays alive — unlike black straight from the tube, which quickly makes night pictures look dull and dead.

Use it to lay in the entire surface: building walls, street, trees, roofs. Work fairly roughly and in large shapes; you don't need details in the darkness. Let the underpainting vary slightly, warmer near artificial light, cooler in the corners where no light falls. Only once this layer is in place and has dried a little do the lights come: windows, streetlamps, shop fronts, headlights and the reflections on wet asphalt. Put them in a strong yellow-orange, and only the brightest cores of those in almost pure white with a hint of yellow. Pure white from the tube looks cold, like a hole in the picture — a drop of yellow turns it into light.

The value reversal

The biggest thinking error with night pictures: we automatically paint the sky darker than the buildings, because that's what we're used to during the day. At night it's usually the other way round. Especially at dusk and in the city, the sky stays the lightest value in the picture for a long time — brightened by scattered light, low-hanging clouds, the glow of the street lighting. The buildings in front of it stand out as dark silhouettes.

For you that means: keep the sky clearly lighter than the roofs, and don't draw the roof edges with a line but as a hard boundary between light and dark. If that one relationship is right, the eye immediately reads "night", even if the rest of the picture consists of just three shapes.

Warm against cool

The real subject of a night scene isn't the building and isn't the street, but the interplay of two temperatures. Artificial light is warm: yellow, orange, sometimes a reddish amber. The dusk sky is cool: blue, blue-green, often a greyish violet towards the horizon. The more consistently you keep these two poles apart, the more the picture glows.

In practice that means: everything that catches light gets mixed with a shot of yellow or orange — the windowsill, the patch of pavement under the streetlamp, the side of a car. Everything in shadow you keep cool and blue. Avoid mixing warm and cool lights together until everything turns beige. It's the proximity of cool and warm that creates the luminosity, not brightness alone.

Few lights that count

A night sketch with thirty glowing windows looks like a starry sky: even and boring. Decide on a handful of lights and give each one a job. One may be the brightest in the picture, two or three secondary ones support it, the rest stay muted or disappear entirely into the underpainting. Different sizes, shapes and spacings make the group interesting.

For a light to really radiate, it needs a halo. Take the light colour heavily thinned with water or medium and pull it softly outwards from the core with an almost dry brush. The core stays hard and crisp, the edge fades. With gouache you can re-wet the edge afterwards with a damp brush; with acrylic you have to be quicker — there it pays to lay in the halo first and put the hard core on top afterwards.

Practicalities in the dark

You'll need a headlamp, but don't point it straight at the palette: its light is usually cool and distorts every colour you mix. Better a position off to the side or from above, or stand in the glow of a shop window. At night, rely more on system than on your eye anyway — you know that lamplight is warm, even if you can barely judge it on the palette.

Expect cold fingers and slower drying: damp evening air and low temperatures noticeably lengthen the waiting time between layers. So plan the underpainting early, while it's still dusk. And if things get uncomfortable, a seat by the café window isn't a betrayal but the smarter solution: warm hands, light on the palette, and the street lying in front of you as a ready-made subject.

Exercise

At the blue hour, find a street with a few lit windows or streetlamps — from a window if need be. Set a timer for 25 minutes. In the first ten minutes, lay in the entire surface with ultramarine and burnt sienna — sky lighter, buildings dark. Then place a maximum of seven points of light: one large and bright, the others smaller and more restrained. Give two of them a softly drawn-out halo. More than seven is forbidden, even if you can see thirty.