HO & O - High Quality Scale Modeling Architecture and Railroading

While the paint is still wet or tacky, use your finger and rub along the length of the chimney. Using a gentle pressure with several passes will take the paint off the surface of the brick. If you see mortar lines

that need more paint, just dab some on with the sponge. If you have paint stiffen up where it will not rub off the brick face, dab on more paint with the sponge. More paint will loosen the paint that's already there so you can rub it off.

My finger is the only tool I have found that will clean the surface and not remove paint from the very shallow mortar lines.

I also use this method (with all four fingers) to paint full sheets of brick and use them for scratch building

structures. Because I use acrylic paint it easily washes off fingers.