The Quest for a Billion Dollar Red

This is an interesting piece in Bloomberg on Mas Subramanian, “the biggest celebrity in the uncelebrated world of pigment research,” and his quest to find a safe and stable red pigment:

The world lacks a great all-around red. Always has. We’ve made do with alternatives that could be toxic or plain gross. The gladiators smeared their faces with mercury-based vermilion. Titian painted with an arsenic-based mineral called realgar. The British army’s red coats were infused with crushed cochineal beetles. For decades, red Lego bricks contained cadmium, a carcinogen.

More than 200 natural and synthetic red pigments exist today, but each has issues with safety, stability, chromaticity, and/or opacity. Red 254, aka Ferrari red, for example, is safe and popular, but it’s also carbon-based, leaving it susceptible to fading in the rain or the heat. “If we sit out in the sun, it’s not good for us,” says Narayan Khandekar, director of Harvard’s Straus Center for Conservation & Technical Studies and curator of the Forbes Pigment Collection. “That’s the same for most organic systems.” One red is stable, nontoxic, and everlasting: iron oxide, or red ocher, the ruddy clay found in Paleolithic cave paintings. “It’s just not bright in the way that people want,” Khandekar says.

Among Subramanian’s 50+ patents is this one:

Patent No. 8,282,728 is for something potentially far more valuable than YInMn itself. In fact, it only briefly mentions “intense blue color.” Subramanian’s true invention was the crystal structure—or the atomic arrangement—of the material, called trigonal bipyramidal coordination. The manganese imparts the blueness, and by adjusting its proportion in the compound, you can lighten or darken its tint. But, as Subramanian’s jars of lilac and mossy green demonstrate, the structure is also capable of absorbing (and, conversely, reflecting) other colors. This discovery was like finding a hidden door in a bookshelf.

Below is a video of how the famous YInMn (pronounced “yin-min”), the bright blue pigment, was accidentally created in Subramanian’s lab (starts at about 3:35 in the video):

Another fact of the day: titanium dioxide accounts for almost two-thirds of the pigments produced globally; valued at about $13.2 billion, it’s responsible for the crisp whiteness of traffic lines, toothpaste, and powdered doughnuts.

From Eye to iPad: The Technology Behind Paper

FastCompany has a profile of the iPad app Paper (by FiftyThree) and the technology behind it:

What vaulted FiftyThree over a hot pile of math was a major insight gleaned from two dead German scientists named Paul Kubelka and Franz Munk. In 1931, they published a paper called Ein Beitrag zur Optik der Farbanstriche, or “a contribution to the optics of paints,” which showed that this color-space question predated computing by several decades. The paper laid out a “theory of reflectance” with an equation which could model color blending on the physical experience you have with the naked eye. That is, how light is reflected or absorbed by various colors.

Today, computers store color as three values: one for red, green and blue, also known as RGB channels. But the Kubelka-Munk model had at least six values for each color, including reflection and absorption values for each of the RGB colors. “While the appearance of a color on a screen can be described in three dimensions, the blending of color actually is happening in a six dimensional space,” explains Georg Petschnigg, FiftyThree’s cofounder and CEO. The Kubelka-Munk paper had allowed the team to translate an aesthetic problem into a mathematical framework.

 Moving from a three-dimensional color-space to six dimensions was the difference between old drab color-mixing and absolute realism. “What creates the shades you see between paints is this interplay of absorption and reflection,” says Petschnigg. “Compare red nail polish to red ink: both are red, but the nail polish will be visible on black paper because it reflects light. The ink won’t be, because it absorbs light.”

Paper is one of the most beautiful apps on the iPad. I highly recommend getting it (the basic version is free) if you don’t have it.