The trademark signature used to identify Lalique items has evolved across different eras of production. Early pieces from the foundational era feature molded, engraved, or hand-etched script signatures such as "R. Lalique." Following the transition into full lead crystal production under subsequent family leadership, marks shifted to include block-letter signatures and acid-stamped stamps reading "Cristal Lalique France" or modern laser-etched inventory numbers that confirm authenticity and manufacturing origin.