When you wish to paint a night sky, it's important to choose a technique and paint type that makes blending multiple colours easy. The watercolour technique known as wet-on-wet is perfect because it causes all the colours used to bleed and blend into each other smoothly and beautifully. Best of all, the technique is very simple to use and only requires a few basic tools. The soft effect of wet-on-wet blending makes watercolours the perfect medium for painting the night sky.
Submerge a sponge in water and squeeze it until all excess dripping has stopped. Press the sponge over the watercolour paper in the area that will eventually become the sky. Make sure to apply an even coat of water across the entire area. The paper should appear shiny, but there shouldn't be any drips.
Add a few drops of water to the watercolour paints of your choice to get them ready for use. Night skies often capture different shades of blue, purple and black.
Dip a soft paintbrush into one of the colours you have selected and glide it across the wet area on the watercolour paper. Use long single strokes that swirl or curve at the ends. Allow the paint to bleed for a few seconds before adding a new colour.
Continue switching between colours on the wet paper until the entire sky area is filled. If a certain area of the paper dries before you can get to it, simply re-wet it with the sponge.