Nearly all shingles start as fiberglass mats soaked with water-resistant asphalt. The top coat is a layer of igneous rock granules, wrapped in a ceramic-pigment coating that protects the asphalt from UV rays. Made in one consistent thickness, these shingles are usually 12 by 36 inches with three to five tabs, or segments—all with the same rectangular shape. Three-tab shingles are the most affordable option and give your roof a clean, uniform look. Choose a color that complements your home’s exterior and fits your neighborhood’s aesthetic.