Paint repeatedly spreads beyond the boundary of a shape while the inner fill remains controlled. Which technical change is most useful?

Correct answer: Use a smaller, less-damp brush and short strokes near the boundary

The governing concept is edge control through brush size, moisture, and stroke length. A smaller brush carrying less water deposits a more predictable amount of paint near a boundary, while short strokes reduce accidental movement across the outline. More water or pouring paint would increase spreading. Using a small brush throughout the interior wastes time and does not specifically solve the boundary problem, where precision is most needed.