How to Paint a Moonlit Night Sky In Acrylics: The Underpainting

Moon Painting Project: Part 1

This simple moonlit scene required just three acrylic colours and white. This sets the scene for the detail (to be applied later with Inktense pencils - see my next demo: Moon Painting Project Part 2).

For now, I aimed only to blend acrylic paints into smooth gradations without concern over complex colour mixes. Deep tones softening into pales brought forward a tranquil sky for the use of soft, wide brushes.

Art Supplies and Materials Needed

• Surface: An A4-sized thick card primed with white gesso or acrylic polymer primer.
• Acrylic Colours: Titanium White, Phthalo Blue, Lemon Yellow, and Burnt Umber.
• Brushes & Tools: Fine/medium bristle brushes, a soft sable brush, a ruler, a soft pencil, rags, and a circular object like a jar lid.
• Note: the finishing touches required Inktense pencils, white, dark blue and fern green.

What you will Learn from this Demo

• How to create contrasts between light and dark.
• Blending a dark, deep colour mix into increasing amounts of white to bring smooth effects.
• Using a limited palette to judge tones.
• To carefully work paint around the geometric area and the moon.
• How to see other colours within white (as seen in the moon).

Step 1: Drawing the Rooftops and Moon

Action: With a soft pencil and ruler, and the aid of a screw-top lid, I sketched out the rooftops and placed the moon on the upper right of the image. 

Don't worry about too much detail here. I placed the roofline roughly a quarter from the bottom of the image and introduced interesting angles and perpendicular shapes into the composition.

Step 2: Blocking In the Greens of the Main Sky

Action: Use a medium bristle brush to apply a heavy portion of phthalo blue mixed with a small amount of white across the top third of the sky.

I used two medium bristle brushes here: one for pales, the other for darks. This meant I didn’t have to keep cleaning one brush between mixes and breaking the flow. I began at the horizon line behind the rooftops. I mixed a little phthalo blue with a tad of lemon yellow into a good portion of white. I then applied this sharp, turquoise green around the outline of the rooftops. The lemon yellow adds a citrus feel as I worked upwards.

Step 3: Blending Smooth Transitions for Dusk

Action: With the two brushes, bring the two green areas of sky together.

With the separate medium bristle reserved for dark mixes, I applied a heavy portion of phthalo blue into a smidgen of white. Phthalo, being an overpowering pigment, can easily look black if used lavishly. I avoided adding too much to the white at first. Notice the shift in tone between the top and bottom of the sky. A balance in tones will be required here.

Step 4: Painting the Rooftop Silhouettes

Action: With a clean brush, apply burnt umber and phthalo blue into the rooftops.

The aim now is to knit together the two turquoise tones. I added more white to the dark brush as I worked downwards, and more phthalo blue as I worked upwards. I had to ensure the tone in the middle would agree. I avoided using too much paint in the middle area, so I could add a little pigment for tweaking. Don’t worry about the patchy bands that may appear on the sky. These can be blended later.

Step 5: Balancing the Tones of the Sky

Action: Briskly cover the lower part of the painting with the dark silhouette colour.

This blending process is an excellent way to practice brush control and colour balance. It demonstrates how subtle tonal transitions can create atmosphere with just three colours and titanium. Once I had covered the sky with the turquoise mixes, I used the bristle (either will do, as both will have similar mixes by now) to knit together the colour bands. Periodically, I wiped off paint build-up from the brush to retain control. A nice blend can be achieved without high perfection.

Step 6: Refining Atmosphere and Contrast

And now for the silhouetted buildings.

I mixed phthalo blue and burnt umber into a clean brush to attain a rich near-black. I don’t usually use pure black (such as lamp black or ivory) for it can deaden the colour mixes. Here, the silhouette comes forth as a cool, sharp, and vivid black. I blocked in the rooftops and chimneys. I worked the paint roughly towards the bottom of the art surface. The simple shapes immediately leap into the composition, bringing unity to the painting.

Steps 7: Painting the Full Moon’s Features

The bottom two images show how I painted the moon. I aimed not for detail, but suggestion and a painterly feel. This sets the moon up for the fine detail with pencil (shown in the next article). With a medium soft sable, I illustrated the rustic features on the moon’s face. I was careful not to go too heavy with the phthalo blue here, for it can overpower the titanium white to be applied next.

Step 8: Colour Mixes for a Green Sky at Dusk

With a clean sable, I applied pure white onto the highlighted areas of the moon and allowed the bluish features to bleed into my white colour mix. Notice the pales become a little greener to the left of the moon. This suggests a light source hitting the moon’s sphere from the right.

I wanted the moon to appear ethereal, ghostly, rather than stand out too much. The moon’s greenish tinge makes it ‘belong’ to the scene. The craters and features on the moon's face will be applied in the next demo.

Finally, I blended a slight halo effect around the moon’s outline to prevent a cut-out feel. The closing stages of the painting always involve a little refining and soft blending. I had to take care not to overwork the painting to perfection.

The Finished Underglaze

See how a limited palette can produce a rich range of tones and hues. The smooth transitions within the sky create a still evening feel, while the dark silhouettes provide structure and contrast.

This demonstration provides an excellent introduction to blending tones and blocking in large areas, while at the same time, restraint in using too much detail, particularly to the moon, for I intend to use Inktense pencils for the finishing touches. The painting is now ready for the next stage.

Further Reading

Read how I finished this moon painting project by adding detail with Inktense pencils.

Read my article on glazing technique on my sister art blog (covering other matters of art).

Or read my focus page on landscape painting on my Oil Painting Medic blog. Or see what’s trending here.