Texes Art EC-12 Practice Exam 2025 - Free Art EC-12 Practice Questions and Study Guide

Gouache is characterized by its opaque quality, which sets it apart from traditional watercolor. This opacity is achieved primarily through the addition of chalk or other white pigments to the paint mixture. The calcium carbonate in chalk acts as a white filler, enhancing the paint's coverage and allowing artists to layer colors without the transparency typical of watercolor techniques.

In contrast, gum arabic, often used in watercolors, serves as a binder that helps the pigments adhere to the paper but does not contribute to the paint's opacity. Oil is not a component of gouache; it defines a different medium altogether, such as oil paint. Solvents, typically used in conjunction with oil paints for thinning or cleaning, are not involved in the formulation of gouache either, which is mainly water-based. Therefore, the correct answer highlights that chalk is the key ingredient that differentiates gouache's opaque properties from traditional watercolor.