Glazed tile features a thin layer of glass on top that gives it a smooth appearance. Unglazed tile, however, lacks this top layer. This leaves the porous surface of the tile exposed, making your tiles more susceptible to stains. Unglazed tile in kitchens or high-traffic areas may become dirty quickly and difficult, or even impossible, to clean. A coat of paint seals the tile and can alter the overall appearance of any tiled surface.
Mix equal parts of water and white vinegar in a bucket or large spray bottle. Add a few drops of liquid dish soap to create a homemade cleaning solution for your unglazed tiles.
Spray your cleaning solution onto the unglazed tile. Scrub with a stiff scrub brush to remove all dirt or grease from the tile's surface. These substances can prevent the paint from properly adhering to the unglazed tile.
Rinse the tile with clean water to remove the cleaning solution. Allow it to dry completely. You can use a towel or dry mop to clean up some of the water to shorten drying time.
Apply an alcohol- or shellac-based primer to the unglazed tile with a paint brush or paint roller. Wait for the primer to dry completely.
Look at the unglazed tile once the primer is dry. The tile may absorb some of the primer during the drying time. If the painted tile appears blotchy or the primer appears to be applied unevenly, add another coat. Continue to apply coats of primer until the tile achieves a uniform appearance.
Paint the dry, primed tile with a latex-based paint in the color of your choice. If you're sticking with the color of the primer, however, there's no need to paint the tile.
Apply two to three coats of water-based polyurethane with a paint roller if the tile is on a floor or patio. This protects the paint from wear and tear caused by people walking on the floor.