Specifically, Wnt7a helps produce the dorsal patterning of the developing limb. Cdc42 is an important regulator of ventral patterning. Many species have colorful patterning on the shell surface. This prevents defects such as cracking, crows feet patterning, and lamination. The method of complementary exposures is another way of reducing mask exposures for multiple patterning. Short term fluorescent patterning and signaling is controlled by the nervous system. Multiple patterning is evolving toward a combination of multiple exposures, spacer patterning, and/or EUV. Koi varieties are distinguished by coloration, patterning, and scalation. Sonic hedgehog (SHH) are morphogens that are essential to early patterning in the developing embryo. Supplementary weft patterning and brocading is practiced in many regions. Optimal facet placement is the key to brilliance and more important than facet patterning. Temporal changes in the amount of white patterning are discussed below. Noggin plays a key role in cartilage and bone patterning. Some knitters may use knitting machines with varying degrees of automatic patterning. Their inner petals are generally very like the outer ones in colour and patterning.