One of the most readily recognizable Persian rugs is the Heriz. Heriz rugs, boldly colored in rust reds and blues, have rectilinear design elements rather than curvy ones found on formal Persian rugs. Most often the design focuses around a large center medallion. However, Heriz rugs without medallions may also be found. The best of the Heriz rugs have a particularly crisp look because the design elements are outlined by two lines of contrasting colors. Heriz rugs traditionally have a thick pile and heavy foundation.