Paint Fit for Other Materials
Rolling color onto wood and drywall is a snap. It’s some of the other materials found around the house that can be tricky. Here, advice on getting the color coating right the first time.
NOTE: If you suspect that old flaking paint contains lead, visit epa.gov/lead for info on proper handling.
Masonry

Such as an exposed brick wall or a stone hearth
Prep: Scour unpainted bricks with a sponge or a nylon brush and warm, soapy water; let dry overnight before priming. On previously painted surfaces, use a wire brush to remove chips and flakes, then smooth uneven areas with 100-grit sandpaper before cleaning.
Coat: Seal pores with a water-based primer designed for masonry, and coat with latex paint. Use a thick-nap roller, and use a brush to cut in along the edges or to get paint into any crevices the roller can’t reach.
MDF

Used for built-in bookcases and cabinets, and interior trim
Prep: MDF (medium-density fiberboard) absorbs moisture and can become “fuzzy,” so skip washing it. Sand unprimed material with 150-grit paper to give it tooth. Factory-primed material is ready for paint.
Coat: To keep the material from swelling, choose a shellac- or an oil-based—not a water-based—primer, covering the cut edges with two coats. Top it off with latex paint, using a small brush to cut in and a short-nap (up to ½-inch) roller for even coverage over large areas.
Metal

Such as radiators, heat registers, and tin ceiling tiles
Prep: Clean unfinished metal with soap and water and a sponge; immediately blot dry if iron or steel. On already painted metal, use a wire brush to remove loose chips, then smooth uneven areas with 100-grit sandpaper before washing.
Coat: Use an oil-based primer on ferrous metals (those containing iron) to prevent rust, or a water-based metal primer on nonferrous surfaces. Opt for latex spray paint, one formulated to handle heat, where needed. Avoid drips by applying several thin coats, letting each coat dry in between.
Plastic

As in kids’ furniture, or outlet and switch-plate covers
Prep: To ready the surface, wipe with an ammonia-based cleaner, rinse with a damp cloth, and let dry. Rough up glossy or previously painted plastic using 150-grit sandpaper so that it will more readily accept the new paint.
Coat: Apply a bonding primer designed for plastic, and coat with latex paint. A wider brush covers in a few passes, minimizing brushstrokes. If you’re not confident about your brush technique, try a 4-inch foam roller or a spray paint made for plastic.