Mechanical engraving enables to create decorative ditches of various profiles on the glass surface. This operation is carried out on special engraving machines. Diamond cutting tool may be of various profiles and thickness due to which it is possible to get great deal of various relief images and ornaments on the glass by means of engravings, according to a corresponding imagination. The image may be both matted and transparent. The cutting cap moves forward and backward on a trajectory of a priori made mechanical copy in an advancing pace till getting the image on the surface with a required depth. The procession is carried out under a water-blast.