Preparing the surface of the brick helps the paint go on easier and last longer. First, brush your bricks clean using a stiff brush. If they have old paint or mortar on them, use a brick cleaning acid to remove it. Use an oil-based primer if the bricks are stained to prevent any stains showing in the finished work.
To paint bricks, use an elastomeric paint, a water-based paint that is high in acrylic, as it's waterproof and can fill small cracks in the bricks. Use a roller designed for use with textured surfaces. You will probably need two or three coats of paint to cover the bricks since they are porous and will absorb some paint. Allow the brick to dry completely between coats.
You can either paint an existing brick fireplace, or construct your own. If you're building a fireplace, first measure the space and make a template on a piece of plywood. Apply mortar to the bricks and place them together tightly, following your template. Allow the mortar to dry, then check for cracks where you might need to apply additional mortar. Use two coats of a good quality paint manufactured specifically to withstand heat, or more coats if the fireplace is used frequently. For a bold look, try painting the bricks a contrasting color to your walls, or alternate colored bricks to make a design. Light colors can brighten a drab room, while choosing a color similar to your walls will make the fireplace blend in to the room.
A bookshelf made of bricks and wood planks is simple to construct and an ideal way to create more storage space. Choose your location, then make two stacks of bricks, spaced apart so you can put the plank on top. Add more bricks and planks as desired. To ensure your bookshelf is sturdy, place the heaviest books on the lowest shelf. Try alternating different colored bricks, or painting designs on individual bricks. For a rustic look, mix two parts paint with one part water, and apply to the bricks using a sponge. If you prefer a clean, modern look, try black and white bricks with glass shelves.
You can use painted bricks for many projects in your garden. Try constructing a flower planter on your patio, choosing colors to complement your favorite flowers. Create a garden path, perhaps using black and white bricks to make a checkered or herringbone design. In the house, try painting patterns or pictures on bricks to use as doorstops or bookends. Use a brightly colored brick with holes in it as a pencil holder or the base for a flower arrangement.