A fine sand that is combined with additives, typically silica, and designed to be used in the joints and spaces between pavers, stones, or tiles. When applied and then moistened, the additives form a binding agent that helps lock the pavers together. This creates a durable and flexible joint that is resistant to erosion, weed growth, and insects, making it an ideal choice for both new installations and repairs of paving stone projects such as patios, walkways, and driveways.