In a landscape painting, the sky affects the tone, mood, and atmosphere of the whole painting.  As painters, we strive for an interesting, perhaps a dramatic sky whether or not that is what we see in front of us.  Clear blue skies can appear bland and less than inspiring.  In a painting the artist hopes to design a sky that helps create the most effective mood for the subject.  Ask yourself, “What does this subject need to make it work well?”

If a landscape or seascape is busy, with lots of details or information, a simple sky treatment might be a good choice. 

On the other hand, a moody, vibrant, or striking sky would complement a composition with a low horizon line, as in a stark, brooding moor or a bold sunset. 

As another example, a roof in the rain could take on a gleam of silver as the sky reflects off it.

It is essential to decide what sort of sky is involved in a landscape painting BEFORE starting the painting.  This statement is true even if a sky will not actually be seen in your picture, because the appearance of the light depends entirely on the sky.  A landscape can be creatively transformed by altering the light or weather conditions in a painting.  Light and shadow, color and mood should be consistent throughout your composition, so skies must be part of your initial planning.

Wilfred Ball, in Weather in Watercolour (1986), describes the “creative transformation” of planning a composition by altering sky and weather details.  “Buildings, walls, gates, fields and mountains tend to be relatively formal features of the landscape, but the effect on them of such variables as the light, seasons and weather is capricious and magical” (p. 9).  And changes in the sky and weather are “merely an extension of the creative process that goes on whenever we paint.  Almost without thinking we strengthen this, weaken that, miss out a tree here, heighten the colour of an autumn tree to focus attention on it.  These devices are all ways of recomposing the subject to increase its impact.  Indeed it is this kind of alteration, that we make to the subject matter as we saw it, that is the creative process in what would otherwise be a straightforward copying procedure.  Using the weather creatively is one of the most effective of all the transformation devices a painter can use” (p. 11).

Thus, you should not be afraid to use a bit of imagination when creating a sky.  Think about the colors you will use in your painting, and have them mixed and ready to go.  Mix up large, juicy puddles of the sky colors you will use.  Mix lots more than you think you will need to insure that you won’t run out or have to skimp while painting!

Have your plan thought out before wetting your paper.  Skies are often painted wet-in-wet, though other techniques (wet on dry, for instance) can also be used.  To begin, wet the sky area with clean water.  As soon as the shine goes from the paper (and when it appears to have a more matte finish), DROP in your colors by floating the pigment across the paper.  Try NOT TO PUSH the colors around, instead letting the colors mix together on their own.  Do not overwork or touch the paint while it is drying.  During drying time, the sky continues to develop ON ITS OWN with a subtle blending of colors.  Timing is all-important.  Don’t paint back into your sky; be assured, and paint with confidence.

To increase the feeling of distance in your sky, lighten the sky toward the horizon.  Colors can be warmer and darker higher in the sky.  Don’t view the sky as separate from the rest of your painting.  Remember: it affects your entire landscape.  You can achieve the needed harmony by echoing the sky colors in the rest of the picture.  For example, include warm sunlight on the side of a building or reflections of a sunset on water or snow.

What colors should you use?  Sometimes you may want to add yellow highlights to a blue sky.  Have you ever laid down a sky with blue and yellow and had it start to turn green where the two colors met?  The effect has something to do with color bias and color mixing.  Certain blues have a red bias (they contain some red pigment), while others lean toward green, and whichever blue you use will react with other colors according to its bias.  If you are unsure how your colors will interact, try several combinations of blue and yellow on test paper.  Alternatively, lay down your pale yellow wash, and let it dry before adding blue.  This way, you will have less chance of creating green, even though you will also lose some of the soft mingling of color that occurs with the wet-in-wet technique.

To avoid surprising or unpleasant color mixes when combining colors in the sky, try arranging your color sequence like a rainbow.  In a naturally occurring rainbow, the colors appear in a sequence similar to (but not precisely the same as) the following; so from the top of the sky to bottom (horizon), you could use:

*Ultramarine (which has a red bias)

*Cobalt (no real bias)

*Cerulean (yellow-green bias)

*Raw Sienna (red-orange bias)

*Permanent Alizarin Crimson (or Perylene Maroon or Permanent Rose) mixed with  Ultramarine Blue. (Be sure not to use too much red.)

Put your colors in bands in this order, just overlapping the edges so the colors soften.  Keep in mind that you needn’t use every one of the above colors in your sky, but use at least two.  Your choices of colors will affect how each color blends with its neighbor when they touch.  Test your colors and technique on a test sheet before applying paint to your picture.  Make sure you understand the affect of your color choices so you can avoid unpleasant surprises.

A sky affects the tone and mood of the whole painting.  Plan ahead for a dramatic, interesting sky that integrates well with the rest of your picture.  The sky will suggest proper placement for shadows and even some of the colors you should use throughout your painting.  For example, strong Mediterranean sunlight will create harder lines and sharper contrast than a misty morning in the Scottish Highlands.  Don’t be afraid to use your imagination when creating a sky.  Don’t paint back into your sky, don’t fiddle, and don’t be impatient.  Instead, try to apply your colors confidently, with a large brush, and let the colors mix together on their own.