What is the main component of watercolors that serves as a binder?

The main component of watercolors that serves as a binder is gum arabic. This natural gum, derived from the sap of acacia trees, has the property of dissolving in water, allowing it to mix well with the pigment to create the watercolor paint. When applied to paper, gum arabic helps to hold the pigment in place and gives the paint its desired transparency and finish.

In the context of painting, gum arabic allows artists to achieve various effects and maintain the fluidity characteristic of watercolor techniques. The use of a water-based binder like gum arabic differentiates watercolors from other mediums, such as oils which use linseed oil as a binder, or acrylics which utilize an acrylic medium. Water itself is a significant component in watercolor but does not serve as a binder; instead, it acts as the vehicle that carries the pigment and binder to the paper.