Asphalt sealer is the lifeblood of every pavement-protection job. Apply it right and you lock in rich color, watertight protection, and a reputation for quality. Apply it wrong and you’re stuck with callbacks, peeling film, and profit-eating rework. Whether you’re a first-time DIYer sealing a small driveway, a facility manager protecting acres of parking, or a full-time contractor running multiple crews, the fundamentals below will keep every gallon of asphalt sealer working for you—not against you.