What is the purpose of masking fluid in watercolor painting?

Masking fluid is primarily used in watercolor painting to retain white areas. By applying masking fluid to specific sections of the paper, artists can protect those areas while painting around them with watercolors. This technique is particularly useful when an artist wants to preserve the brightness of the paper, which serves as the white of the painting. Since watercolors are transparent, once the masking fluid is removed after the painting is complete, the untouched white areas will stand out distinctly against the color washes applied to the remaining parts of the artwork.

This technique allows for greater flexibility and creativity, as it enables artists to include highlights and light-reflecting surfaces without needing to plan these aspects too rigidly in advance. The ability to mask off certain areas also lends itself to various effects and creative approaches within watercolor painting.