Watercolour paints are fine-ground pigments in binders, such as gum Arabic and tragacanth, which are water-soluble. Both organic and inorganic watercolour pigments are available, such as vegetable, animal, native earths and synthetic colours. Watercolours are primarily sold in tubes and pans, with many colour selections to choose from. When using watercolours to paint water, it is important to consider the characteristics of the body of water you wish to render, be it a lake, stream or the ocean.
Lay out newspaper and fill two jars with water, one of which will be used for cleaning your paintbrushes, and one for mixing paints. If using tubes of paint, squeeze out small amounts of the desired colours onto the palette. Set out your paintbrushes and canvas.
Sketch out the area of the water on your canvas. This can range from a small pond in the corner of your painting, to an ocean scene where the water is the focal point.
Using the large paintbrush, mix a liberal amount of water with a blue colour of your choice. Using broad strokes, cover the area with a light wash of blue.
Using darker blues, add different levels of depth to your water. For example, if you are painting a lake or the ocean, layer a dark blue at the bottom of the water.
Add in several other layers of depth as you build up toward the surface of the water. This adds an element of realism to your work. If you are painting a small or shallow body of water, skip the dark lowest level.
Using the large paintbrush and a small amount of water, blend together the different shades of blue.
Incorporate any additional desired colours, such as green or brown. Do this with the large brush in the same way you painted the water.
Using the small, thin paintbrush, add finishing touches such as waves and reeds. Small, thin lines of white paint will create waves, and a brown oval on top of a thin green stem will create a reed on the bank of the water.
Remember that less is more when it comes to using watercolours. Too much water can lead to the paint running on the canvas. If you only have one blue watercolour paint, vary the amounts of water to produce different shades.
Exercise caution, as paint can stain some types of clothing.