Swiss stamps from the 1800s: what their colors reveal

Swiss postage stamps from 1850 to 1908 weren’t just about postage. They were tiny canvases showing off the best pigments and dyes of the time. For the first time, researchers closely examined 98 of these stamps using advanced tools like Raman spectroscopy and scanning electron microscopy. Instead of guessing what colors made these stamps pop, they broke down every shade and ink used. Blue was a big deal. Many stamps used Prussian blue, a deep, rich pigment that became popular in Europe. But early versions often relied on ultramarine, a brighter and more expensive blue made from ground-up minerals. The choice between them tells a story about cost, availability, and even trade routes at the time.Red was where things got interesting. Early stamps mostly used inorganic pigments like vermilion and chrome orange—bright, long-lasting, but sometimes toxic. Later stamps switched to organic dyes like eosin Y and carminic acid, which came from natural sources like insects and plants. This shift wasn’t just about color; it pointed to changes in chemistry and how people viewed safety in everyday objects. Green stamps were made by mixing blue and yellow pigments, just like in paintings. Chrome yellow was a common choice, though it faded over time. Brown and gray stamps were the simplest: mostly carbon black with a hint of red or white to tone them down. Every color choice was a trade-off between durability, cost, and what was trendy at the moment. These tiny stamps weren’t just for mailing letters. They were snapshots of 19th-century science and industry. By studying them, researchers aren’t just learning about stamps—they’re uncovering clues about how people in the past made decisions, used resources, and even what they valued in their everyday tools.