Properties of Watercolor

Watercolor Materials
Watercolor Effects

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 the medium.
Watercolor Materials

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 Surfactant is one of the most important incredients in watercolor. It allows water to be soaked into the paper.

Binder 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 artists.
Watercolor Effects

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

Dry-Brush (a)
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.

Flow Patterns
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
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 discussing.