Hand-knotted rug quality begins beneath the surface, with the structure of the rug itself. Unlike machine-made rugs, which rely on a mechanized backing, a hand-knotted rug is built knot by knot around a warp-and-weft foundation, often using wool, cotton, silk, or a considered blend of natural fibers. Examine the back of the rug for visible rows of individual knots and a pattern that remains legible in reverse; a clear, consistent weave is one of the most useful indicators of authentic hand-knotting. Knot density can offer insight into detail and labor, but it is not a standalone measure of quality. A finely knotted Persian rug may hold intricate floral motifs, while a more generously spaced tribal or vintage rug can be equally durable and compelling. Look for a balanced foundation, secure edges, an even—but not mechanically perfect—pile, and a weave that feels structurally sound rather than stiff or overly uniform. Small variations in knot size, color, or alignment are often evidence of human workmanship, not flaws. The materials and finishing details matter just as much. High-quality wool should feel resilient and pleasantly substantial, with enough lanolin or natural softness to help the pile recover from everyday foot traffic; silk can create luminous highlights and exceptional pattern definition, but it generally calls for gentler placement and care. Inspect the pile for consistent shearing, healthy color, and signs of wear that suit the rug’s age, particularly with vintage hand-knotted rugs. Abrash—subtle shifts in tone caused by changes in dye lots or yarn—can lend a one-of-a-kind rug the atmosphere of a faded fresco, while dramatic thinning, exposed foundation, unstable fringes, or brittle fibers may indicate repairs or areas requiring professional attention. Trustworthy rug sellers should identify whether a piece is vintage, newly made, restored, or repaired, and provide useful details about its materials, origin, dimensions, and care. The best hand-knotted rugs bring together a durable construction, honest signs of the making process, and a surface that grows more characterful with use.