A frog (sometimes referred to as a Chinese frog) is an braiding for fastening the front of a garment that consists of a button and a loop through which it passes.
The purpose of frogs is to provide a closure for a garment while decorating it at the same time. Frogs are often used on garments that appear Asian in design. Tops with a mandarin collar often use frogs at the shoulder and down the front to keep the two sections of the front closed.
Frogs are usually meant to be a design detail that "stands out". Where many frogs are repeated beyond any reasonable needs for fastening, this purely decorative form is termed 'frogging'.
Frogs and frogging became an important decorative feature on military uniforms from the 17th–19th centuries. This was particular evident for prestigious regiments, especially cavalry or hussars, and gave rise to the German term for frogging in general, ''. These dolman jackets were tight-fitting and dominated by extensive frogging, often in luxurious materials such as gold, silver or brass metallic cording or brocades.
The frogging was usually far more than was necessary for fastening. In some cases it even became non-functional, with a concealed opening beneath it and the original jacket opening becoming a false detail. By the later 19th century, for lower grade uniforms down to postmen, telegraph boys and hotel pages, the frogging cordage would be retained as a decoration but there would be no corresponding toggle or opening with it.
Many sewers make their own frogs because the results are customizable. Self-fabric can be used to create frogs that are the same color as the garment, though frogs are usually chosen to be a contrasting color to that of the garment.
Frogs are made by looping and interlocking the cording or fabric tube into the desired design, then securing the places where the cords touch by hand-sewing. The frog is then stitched onto a garment, usually by hand. When a fabric tube is used, the fabric is cut on bias. This allows the fabric tube to remain smooth and flex easily when bent into curves.