Registered designs. Infringement will lead to prosecution.
Grooves are cut into the glass which is then cut, using a chisel, between these grooves.
The effect is one of chips and splinters that diffract the light. The size of these chips is determined by the chisel and the force applied to it. The greater this force, the thicker the glass must be.
The chiselled forms can be untouched or the contours engraved to give more definition.
Chiselled glass can also be coated with metal or a coloured finish.