Two new Artistic Barometer postcards with cobalt humidity indicators are now available in the shop.
Two new Artistic Barometer postcards have been added to the shop: “Cyclist in a Puddle” and .
Both cards are functional cobalt hygrometers. Their humidity-sensitive areas contain cobalt salts and change colour with atmospheric moisture, from blue in dry conditions to pink in humid conditions. The cyclist card uses the puddle as the indicator, while the fortune-teller design uses the crystal ball.
Each postcard measures 10 × 15 cm and has a blank reverse side. They combine a traditional chemical method of indicating humidity with a decorative format inspired by historical weather cards.
