Why is it important for paint to be stable?

Stability in paint is crucial for preventing negative interactions with other layers. Stability ensures that the properties of the paint remain consistent over time, which is essential when layering different mediums or adding protective varnishes. If a paint is not stable, it may react adversely with subsequent layers, leading to issues such as discoloration, peeling, or flaking. This can compromise the integrity of the artwork and affect its appearance and longevity.

While considerations such as glossiness, color mixing, and vibrancy are also important traits of paint, they do not encompass the critical aspect of maintaining the structural coherence of an artwork across multiple applications. Ensuring that paint is stable ultimately preserves the artist's intention and the overall quality of the final piece.