Repoussé , or embossing, is a metalworking technique in which a malleable metal is ornamented or shaped by hammering from the underside. There are few techniques that offer such diversity of expression while still being relatively economical. While repoussé is used to pry out the reverse of the metal to form a raised design on the front, chasing or engraving, is used to refine the design on the front of the work by sinking the metal. The techniques of repoussé and chasing utilizes the plasticity of metal, forming shapes by degree. There is no loss of metal in the process, as it is stretched locally and the surface remains continuous. The process is relatively slow, but a maximum of form is achieved, with one continuous surface of sheet metal of essentially the same thickness. Direct contact of the tools used is usually visible in the result, a condition not always apparent in other techniques, where all evidence of the working method is eliminated.