Titanium white
The whitest white ever made, and by a wide margin the most-produced pigment on earth. Titanium dioxide is in paint, paper, plastic, sunscreen, toothpaste and the icing on cakes, and it arrived in the artist's studio as a side effect of an industrial revolution in coatings.
Origin
Titanium is abundant in the earth's crust but stubborn to isolate, and usable white titanium dioxide was not produced commercially until 1918–1921, when processes were developed independently in Norway and the United States. The pigment reaches the market in two crystal forms: anatase, the earlier and slightly chalkier version, which turned out to catalyse the breakdown of the binder around it, and rutile, developed in the 1930s, which is denser, more opaque, marginally warmer and chemically inert. Essentially all modern titanium white is rutile, usually coated with alumina or silica to suppress its remaining photocatalytic activity.
In art history
It reached artists' colours in the 1920s and became the default white of twentieth-century painting within a generation — the white of Abstract Expressionism, of Pop, of everything painted with acrylics, since it is the only white that performs well in a water-based emulsion. In this atlas it appears in three eras, all of them late, and its presence is a reliable terminus post quem: a painting containing titanium white cannot predate 1920. That fact has retired a number of forgeries, most famously in the case of works attributed to Old Masters that turned out to contain a pigment invented four centuries too late.
In the studio
Its defining property is hiding power. Titanium is roughly twice as opaque as lead white and many times more opaque than zinc, which makes it superb for covering and awkward for everything else: a small amount overwhelms a mixture and bleaches it to a pastel, and painters trained on lead white find its tints chalky and inert. It has no warmth. It dries slowly in oil and forms a soft, weak film, so it is usually sold blended with zinc or with fillers to improve handling — which reintroduces some of zinc's brittleness. In acrylic and in commercial paint it is unproblematic and universal.
Afterlife
Nothing has displaced it and nothing is likely to; the questions around it now are environmental and regulatory rather than technical. Titanium dioxide production generates large volumes of acid waste, and the European Union banned the pigment as a food additive in 2022 over concerns about inhaled and ingested nanoparticles — a restriction that does not affect its use in paint, but which has made the most ordinary substance in the studio unexpectedly controversial.
Where it appears
Every era and artist in this atlas whose palette includes this pigment.