Set of 2 flared crystal glasses engraved guilloche scrolls art deco 1920 champagne cocktail cup

This pretty set of two flared glasses is made of very fine crystal. These are champagne glasses or cocktail glasses with acid-etched guilloché decoration. The pantogravure decoration is elegant: a guilloché ornament of foliage with delicate scrolls. This technique is presented at the baccarat museum: the glass was coated with wax and the decoration is drawn with a pantogravure needle in the wax, then the glass is immersed in an acid bath which attacks the bare crystal. These old glasses are not signed. In good condition, they measure 9.2 cm X 8.7 cm in height. I report a chip on a glass.