1. Before adding the final layers of paint, she decided to underpaint the canvas with a light wash of color.
在最后涂上最后的颜料之前，她决定在画布上做浅浅的上色。
2. The artist used an underpainting technique to establish the basic composition of the landscape before adding more detailed elements.
艺术家使用底层上色的技巧，在添加更详细的元素之前，确定了风景的基本构图。