What property of paint helps give it a unique brush stroke appearance?

The property of paint that contributes to its unique brush stroke appearance is consistency. Consistency refers to the thickness or viscosity of the paint, which affects how it behaves when applied with a brush. A thicker consistency allows for more visible and defined brush strokes, as it holds its shape and texture better on the surface. This means that artists can manipulate the paint more aggressively, resulting in distinct marks that reflect the movement and technique of the brushwork.

In contrast, other properties like light fastness relate to how well the paint maintains its color when exposed to light, and permanence concerns the longevity and durability of the paint over time. Drying rate pertains to how quickly the paint dries, influencing layering and blending techniques in an artwork but not the intrinsic texture or stroke definition itself. Thus, while these factors are important in their own right, they do not directly contribute to the visual characteristics of brush strokes as consistency does.