Properties of Watercolor
The origins of watercolor began as thin colored washes being applied to painstakenly
drawn pen-and-ink or pencil drawings. The modern style of watercolor dates back
to the 18th century with such artists as J. M. W. Turner, John Constable and David Cox.
They developed the methods that are still in use today, such as the wiping and scratching
out technique. They explored these techniques along with the immediacy and spontaneity of
Watercolor paint is composed of pigment particles suspended in a solution
of water, binder and surfacant.
Watercolor paper is made from linen or cotton rags that have been pounded
into small fibers, instead of the standard wood pulp. The paper is composed of a microscopic
web that is extremely absorbant to water. To limit the absorbance of the paper sizing is
added. This addition allows the liquid paints to be usedon the paper without the paint being
immediately soaked in.
Sizing is applied to watercolor paper so that liquid paints won't be immediately absorbed into
the paper. It forms a barrier that slows the rate at which the water is absorbed and diffused
into the paper. Sizing is usual composed of cellulose, which is hightly resistant to water.
Watercolor pigment is basically a solid material in the form of small, separate particles that
are suspended in a solution. Pigments are ground into grains that range from 0.05 to 0.5 microns
in size. At this size they can penetrate paper, but once they are in the paper they can't migrate
very far. Pigments differ in density and in their ability to adhere or to coat paper fibers. Different
pigments exhibit granulation or flucculation.
Granulation is the property of certain pigments where particles settle into the hollows of the paper.
Flucculation is the tendency for pigments to be drawn together into clumps. This tendency is usually
caused by electrical effects.
Surfactant is one of the most important incredients in watercolor. It allows water to be soaked
into the paper.
Binder allows the water to soak into sized watercolor paper.
Watercolor paper must have a balance of both sufactant and binder to allow the
watercolor paiint to exhibit the qualities that are desired by watercolor
Before we can go into the different effects used in watercolor we must discuss the
different painting techniques used. The first technique that is used in watercolor
is wet-in-wet painting. Wet-in-wet painting is when the the paintbrush is loaded
with paint and is applied to watercolor paper that is already saturated with water.
The result is that the paint is allowed to spread freely on the paper. The second
technique is wet-on-dry painting. This technique describes using a brush to apply
watercolor paint onto dry watercolor paper. The different effects that can be created
using these techniques can be seen below
The dry-brush technique is the technique of using an almost dry brush to apply
paint at a certain angle that will cause the paint to only cover the highest points on
the paper. This technique fills the stroke with holes and ragged edges.
Edge Darkening (b)
Edge darkening is created using the wet-on-dry paint method. The sizing in the paper
combined with the surface tension doesn't allow the brushstroke to spread. As the water
evaporates from the paint, the pigments in the paint flow towards the edge of the stroke.
Thus causing the edge of the stroke to be darker than the rest of the stroke.
Ententional Backruns (c)
Intentional backruns occur when a puddle of water spreads back onto a damp area of paint.
The water causes the paint to spread out in branch-like patterns with rather dark edges.
Granulation and Separation of Pigments (d)
This effect creates a grainy texture that highlights the peaks and valleys in the
watercolor paper. This effect is strongest when the paper is very wet.
Is created using the wet-in-wet technique. The wet surface of the paper allows the
brushstroke to spread freely. This effect results in a stroke that follows the flow
of the water on the paper.
Color Glazing is perhaps the most important effect in watercolor painting. It is created
by adding very thin, pale layers, or washes over one another. This effect not only creates
new colors, but some say it give a luminous effect to the painting.
The image that you see below are strokes that were simulated using the methods that we will be