Series of 5 old crystal cups engraved with bacloché volutes guilloché volutes?

These beautiful acid-engraved glasses are probably made of baccarat crystal. There are 5 of them, it is a flared model, a form of cut. The pantogravure décor is elegant: a guilloché ornament of rinses with delicate scrolls. This technique is presented at the baccarat museum: the glass was coated with a wax and the decoration is drawn with a needle in pantogravure in wax, then the glass is immersed in an acid bath that attacks the crystal bare. These old glasses are not signed. In good condition, they measure 9.2 cm X 9.2 cm in height. I point out a splinter on a glass.

Ref. : V47SVAKG