In the 19th century, perfumes became widely available and bottles reflected different designs and preferences, ranging from simply to very elaborate.

 

Opaline glass is known for its semi-opaque appearance and delicate translucence.  It was mostly produced in 19th century France by adding materials such as bone ash to lead crystal, resulting in a milky, opalescent effect.  The resulting glass resembles porcelain.   An overlay occurs when a layer of glass is applied over another.  This can allow for a variety of visual and decorative effects.