Frog (fastening)

A frog or pankou (simplified Chinese: 盘扣; traditional Chinese: 盤扣; pinyin: pánkòu), also called Chinese frog closure and decorative toggle, is a type of ornamental garment closure. Made from braiding, cord, fabric, or covered wire, they consist of a decorative knot button (a Chinese button knot for a traditional Chinese style) and a loop. Its purpose is to fasten garments while providing a decorative element on the clothing. It can be used to fasten openings edge-to-edge, avoiding an overlap. It is especially used on the cheongsam, where the pankou represents the cultural essence of the dress.

The frog was first developed in China; the origin of its later spread, into Europe and beyond, is uncertain. Loop-and-knot fasteners may have developed independently in other cultures. In Western Europe, military uniforms adopted a similar decorative fastener from Hungarian Hussars (who possibly had adapted them from earlier Chinese or earlier Ottoman styles, or may have independently developed an analogous fastener) which then began to appear on the civilian clothing of both genders, such as overcoats, spencers, and pelisses.

Frog fasteners are usual to garments with Chinese-influenced design, such as a shirt or coat with a mandarin collar, which features frog fasteners at the shoulder and down the front of the garment. In the design of a garment, frogging is the use of braided frog fasteners as a detail of the overall design of the garment.