Of the vast numbers of ceramic tile available for house and garden, terra cotta tiles are perhaps the most widely selected for outdoor use. The term terra cotta, meaning baked earth in Italian, typically refers to rather rustic-looking tiles that are colored in warm, earthy, and natural tones. Within the terra cotta family, however, there are several types of tile -- some glazed, some unglazed, and all with slightly different characteristics.
Hand-molded, unglazed tiles, sometimes called Mexican pavers, usually have an uneven surface and a handcrafted look. And while their informal, rustic appearance rates high, they are soft and porous and should be sealed to reduce water absorption. Unglazed pavers are also apt to deteriorate in cold climates. Machine-made terra cotta tiles, commonly called quarry tiles, tend to be harder and more durable and may be found in glazed and unglazed forms in a variety of shapes and sizes. Most glazed tiles have a smooth finish and resist stains beautifully, but a too-smooth glazed surface can be slippery when wet.