Which method is best for preventing paint from seeping beneath stencil edges?

Correct answer: Dab vertically with a sponge carrying little paint

The governing stencil principle is to control both paint quantity and direction of application. Loading a sponge lightly and dabbing vertically deposits colour on the open area without pushing wet paint sideways beneath the stencil. Therefore, option C produces cleaner edges. A very wet brush, a loose stencil, or paint pushed toward an edge increases the chance of seepage and blurred shapes.