The process of repoussé work in its first stage was somewhat similar to casting. A model was made in wax, from which a mould in a hard metal was cast, and on this hard mould was placed a thin silver or copper plate, which was then beaten into the mould with a hammer till it received its final form. This process was a long and difficult one, and required much skill; consequently the number of repoussé medals is very small as compared with those which were cast. Repoussé work had one great advantage, that of obtaining a high relief, and on good medals, a striking effect. Not unfrequently, especially in Germany, the mould was made of wood, and the plate then hammered into it; but this method was not so satisfactory, as the degree of sharpness was much lessened. The process of engraving was more simple; but perhaps not less difficult. The medals were executed by direct incision with the graver or dry point on a plate of silver or steel, and thus every line told, and the excellence of the work depended upon the accuracy and sharpness of the outline. In the case of struck medals, the die was engraved or cut in steel, which was hardened, and from which proofs were struck in gold, silver, copper, &c. This process was not at first successful, as the mode of striking was simply by the hammer, by which means sufficient force could not be obtained. This was, however, obviated by the invention of the screw, which was first adopted in the sixteenth century, but did not entirely supersede the use of the hammer until the middle of the seventeenth century. Medals are now as a rule produced by striking. [Sidenote: MEDALLIC ART.]