This regular collar shirt is made of shadow check wool, one of the main original fabrics for this season. The warp threads are spaced apart (air feathers), creating a shadow pattern by paying careful attention to the structure of the yarn, even though the warp threads are a single plain type. The weft threads are made of three types of yarn: 1) thin yarn for a light and firm texture, 2) medium-thick, voluminous yarn, and 3) wool tam yarn to give the entire fabric a voluminous and warm feel. You can see the change in the shape of the weft thread through the gaps in the air feathers.