Clouds and their Formations
by Dolores Saul

Since time immemorial the ephemeral play of those cotton-puffy or darkly threatening shapes we call clouds has captured our imagination and sparked our curiosity. Clouds have inspired poets and artists, although essentially they are nothing more than humidity in the air.










While they glide along they let us dream, and only a sky with clouds can bring our landscape scene to life.
Before we include clouds in a landscape, we should know about their most frequent formations. There are differ-ent types depending on wind, weather and temperature. I always watch clouds, how they move and change constantly. I try to take photos of the most interesting shapes.

About the nature of clouds:
Depending on the tempera-ture in the troposphere, water vapour is accumulated
until the air is saturated. Thus snow, mist and dew owe their existence to clouds.
In the lowest layer, at a height of 3 km, you'll find cumulus and stratus cloud fields. Altostratus and altocumulus clouds sail in the middle layer, at a height of up to 6 km. Cirrus (ice) clouds exist in the highest layer from 6 up to 17 km. Cumulonimbus (thunder clouds) form in all layers.
About the appearance of clouds:














On clear and sunny days cumulus clouds are the most common. They resemble big masses of cotton wool and while they drift through the sky we can see their colours change. The side which faces the sun is usually very bright. They have flat bases and the top and sides are bulging into cauliflower shapes.










Stratus clouds are most common in winter. They are the lowestforming cloud forma-tions; looking like layered fog they give us those nearly featureless grey skies. They are quite easy to paint: just put in a few horizontal bands!
Cumulonimbus clouds are the biggest cloud formations; their top sometimes resembles an umbrella or a blacksmith's anvil. They often develop into storm clouds on warm summer days. Dense and dark, they can produce rain or hail.

Altocumulus clouds are small fleecy cloudlets. They appear at sunrise and sunset on clear days in patches or rows. They are white or grey and shaded on the side away from the sun. They are difficult to paint, as they have to be arranged in a kind of zigzag pattern which is influenced by the wind direction.








Stratocumulus clouds come in patches, sometimes joined up or with sky gaps in between. They are the most widespread of all clouds. They hang low in the sky and come in colours from white to dark grey.
Cirrus clouds are the highest of all clouds and consist entirely of ice crystals. We see them on clear days rising like smoke with the wind. They are delicate, ethereal structures which often resemble locks of hair; hence their Latin name.








When painting clouds, there are two different techniques I use to start the painting:

1) For the delicate cirrus clouds, I paint the blue of the sky in a very thin layer. Be careful: if the surface is too saturated with pigments, it becomes nearly impossible to paint in the clouds. In that case it helps to remove the excess layer with a spone brush. Because this is a sunset scene, I paint the cirrus clouds with a light reddish orange. Atten-tion: Don't layer yellow over the blue, even if the clouds show this colour! The yellow combines with the blue, changing it into an unnaturallooking green.









2) I determine the form of the clouds with a simple drawing and start with the skyblue. I use three different Sennelier blues (Sennelier 259,774,296) and let the sky become lighter towards the horizon.
















I apply the pigments in swift strokes with the broad side of the pastel stick. I leave the border of the clouds 'clean', so the lightest sunlit side really stays white and doesn't turn muddy. Here too, one needs to be careful! When the tooth of the sanded paper (e.g. Sennelier Pastel Card) is filled with pigments, additional colour can't be added. For cumulus clouds I add a touch of vermillion red (Sennelier 085) and shade with grey tones and a bit of blue. With a fingertip I carefully blend the pigments from dark to light. Then I turn to the landscape below; don't forget to apply touches of vermillion red to connect sky and land. This colour can appear on fields, forest or even the surface of water, because light shines through the clouds. It creates atmosphere and helps to introduce depth into the painting.
Things to keep in mind:
Season, time of day and weather
Work fast and loose to stay creative
Use the whole value range
Don't paint too many layers; otherwise your sky will turn into muddy grey.
Happy cloud -painting!