Typically priced at around $10 per ton, sand is the least expensive material used in masonry construction. Consequently, contractors sometimes overlook its importance, yawning "sand is sand is sand." But sand actually deserves considerable attention, for it affects the compressive strength, bond strength, workability, board life, drying shrinkage, and appearance of mortar. In mortar, water and cementitious materials form a paste that fills the voids between sand particles, coating and lubricating the particles to create a workable mix. Sand characteristics affect the flow and body mortar needs in its plastic state. As the paste hardens, sand particles become cemented together and contribute to the structural properties of hardened mortar. Sand reduces shrinkage that occurs in setting and drying; thus it helps minimize cracks. Well-graded sand features a well-distributed mix of particles of varying sizes, which minimizes voids. Sand that is too fine has more surface area to coat. Coarser sand particles result in larger voids to fill. As a result, mortar made with sand that is too fine or too coarse contains more water per unit volume, which decreases the mortar's strength. Excessively fine sand also makes mortar less workable.