《宋书·志·卷三十》
最初制作白蛤，在前方横着缝缀以便区别恰的前后，逭哈的横缝被称之为 颜 ，这种缝缀方法在民间流传开来。
初为白帢，横缝其前以别后，名之曰 颜 ，俗传行之。
White clams were originally made with a horizontal stitch in the front to distinguish between the front and back of the garment, and the horizontal stitch was called “face”. This stitching method became popular among the people.