A knop is the thickened node or swelling positioned along the stem of a drinking glass. It serves both a functional purpose for holding the vessel and an aesthetic role in defining the silhouette. Different periods favoured varying numbers and shapes of these nodes, ranging from simple single buttons to complex multi-knop configurations.

How do I date these glasses?

Dating relies on observing the form of the bowl, the construction of the stem, and the characteristics of the foot. Early 18th-century pieces often feature heavy baluster stems and folded feet, while later Victorian items show moulded patterns and brighter colours. Material composition and pontil marks on the underside further help establish the manufacturing era.

What colours do they come in?

While many early examples appear in clear lead crystal, subsequent Victorian periods introduced rich hues such as Bristol green and turquoise blue. These coloured varieties often manifested in rummers, celery vases, and wine glasses. The tints derived from metallic oxides added to the molten batch during production.