Tapio Wirkkala carved the Ultima Thule mould from wood in 1968 and then spent over a thousand hours at the Iittala works with the blowers getting it right. Hot glass burns the wooden mould as it cools; the char is what makes the dripping-icicle surface, and the blower has to judge the moment to stop, because pattern and tone move as the wood goes darker.

The design system takes the 1968 object at face value: no pigment, no cut facets, no staging. A pale cool ground, grey-blue where the glass falls into shadow, wide margins, and a single motif — vertical runs of uneven length hanging from a horizontal edge.