Tender’s spirits glasses are mouth-blown and hand shaped in England from clear or coloured lead-free glass. They are small enough to be used for sharp shots, but they also have enough room to allow whisky to breathe.
Rather than being cast or mechanically mould blown, as most glassware is today, this spirits glass is free-blown in the manner that glass has been worked since the First Century BC. During the blowing process, the rod on which the piece is made leaves a ‘belly button’ or punty mark on the base. The punty mark is sometimes ground away, to leave a perfectly smooth bottom, but to show its construction story, Tender’s spirits glass has the punty mark still showing.
The final stage of production is to press one of Tender’s lost wax-cast solid brass jeans buttons, showing Plautus’ face, into the soft glass base. Then the glasses must be carefully placed in an annealing oven, which cools them down very slowly, over twenty-four hours, so that the glass does not crack.
These spirits glasses are free blown and so vary slightly from piece to piece, however they all measure approximately 2¾” (7cm) tall, by 2½” (6cm) diamter. Mouth-blown glass should be washed by hand, and is not suitable for microwaves, ovens, or dishwashers.