step

In glassware manufacture, the step is a small collar or button of glass that joins the stem to the foot of a drinking glass or goblet. It sits at the base of the stem, where the stem's diameter widens abruptly to meet the foot. This junction is both structural and visual: it must support the weight of the bowl and stem above it while forming a clean, visible line on the finished piece.

The step forms during the glassblowing or pressing process. When a stem is drawn up from molten glass, the glassmaker or pressing machine creates a deliberate thickening at the bottom of the stem before fusing it to the foot. In hand-blown work, this may be done by reheating the join point and allowing gravity and surface tension to form the button. In pressed glass production, the mold itself defines the step's profile. The height and diameter of the step vary by design, from a barely perceptible ring to a pronounced collar up to 10 millimeters across.

Common defects occur when the step is insufficiently fused to either the stem or foot, creating a weak point prone to snapping. Uneven cooling or reheating can cause the step to develop a stress fracture invisible to the eye until the glass is tapped or subjected to thermal shock. A step that is too thin provides inadequate structural support; one that is too thick looks clumsy and consumes excess material.

The step's name reflects its visual appearance: it looks like a small step or tread where the stem meets the foot. In some glassmaking traditions it is called a knop (from the Dutch knoop, meaning knot or button), though knop more often refers to a deliberate decorative swelling on the stem itself. The distinction matters: a step is always present and functional, while a knop is applied for ornament.

The step is fundamental to glassware design across utility and decorative work. Wine glasses, water goblets, and chandelier components all rely on a properly formed step for both durability and visual proportion. In production quality control, inspectors check each piece for step integrity under overhead light, feeling the join with a fingernail for cracks or weak bonding.