The crystal engraver works on the crystal after it has been hot worked and cooled. He usually uses a diamond point, but he can also use acid or a grinding wheel with copper, steel, or emery wheels. The 17th century saw the birth of the delicate and meticulous technique of stipple engraving, which also uses a diamond chip as an instrument. This technique allows for the creation of nuances and reliefs on the surface of the crystal. Crystal engraving requires more than ten years of experience to master all its aspects. Lalique’s engravers are renowned for the finesse of their work.