Is the size of the crotch appropriate or not? The key is in the back crotch, the back crotch is appropriate or not? The key is to open the crotch, because the crotch is the structure of the back crotch from the warp to the weft direction. Open crotch size, according to the routine it is about 1 / 10 of the hips, so open crotch width design, are in the hands of 10-12 cm, it is from the back crotch arc slope (hip position) extending down, straight to the front and front crotch is formed around the crotch cross end size. Its function is not only to ensure that the front and back crotch connection, operation freely, and is responsible for the size of the hip to cross crotch size transition, so the crotch size, arc should pay attention to fit. Open crotch dig through the large, it will increase the potential of tight crotch, open crotch dig degree is not in place, it will cause the hook crotch, dig the size according to the experience of the base, preferably in 2.2--2.5 cm, or from the hip line and open crotch width for a straight line, to the center of the 1 / 2 and 1 / 3 depth arc (see chart 8). This road arc may seem not too long, but to maintain consistent eye ornaments and the human body, but also can shape the process style trousers of the unique contour lines needed to explore characteristics of various shape from the practice, a good grasp of the arc formed. The curve of the crotch, the top and the slope of the back crotch. The slope of the back crotch, it is the hip to the waist of the backward, up and then Alice, lower crotch, so the slope of the back crotch, must also be in the stability of the law. After the crotch slope practice, the following are common: after the body midline and hip bottom line (transverse crotch) as the base point, as 7 cm 8 cm square, both for hip position, As the base and back crotch slope (see chart 9) to the predecessor of the pants in front of the waist line, head, backward for a L / 2 seat slope (see Figure 10.); to cross crotch is a horizontal line, with open crotch width as the starting point, 100 degree angle, and the back crotch slope (see Figure 11), this method is relatively simple and applicable.
