Fraunhofer — Spectra Mug

The sun's own spectrum, wrapped continuous — and across it the dark lines where light goes missing. Fraunhofer mapped them before anyone knew their cause: cooler gas absorbing the colours it would otherwise emit.

Printed edge to edge on an eleven-ounce mug, the band runs the full visible range with the principal lines marked in Fraunhofer's lettering — C and F for hydrogen, D for sodium, b for magnesium, the rest for iron, calcium and oxygen.

Spectra reads matter by its light. Here the light is sunlight, and the gaps are the reading.