The Renfrew tumbler is mouth-blown by master glassblowers to create the weighty, cylindrical, modern glass. The rim is fire-polished to achieve a smooth finish. The wooden coaster is shaped from American walnut, which is treated with food-safe oils to bring out the grain and depth of color. The wood is sourced from sustainably-managed forests and certified by the Forest Stewardship Council. Each glass is mouthblown using centuries-old craft techniques, echoing the traditions of whisky distillation. Expert craftsmanship is required to mouth blow and finishes each glass by hand. A modern interpretation of traditional whisky drinkware.