tempera

Tempera comes from the Italian verb temperare (to mix in the correct proportion, to moderate, to temper), from Latin temperare (to mix correctly, to moderate, to regulate) — from tempus (time, right measure), related to the concept of something that is properly measured or proportioned. The same Latin root gives English 'temper,' 'temperature,' 'temperament,' 'temporal,' and 'contemplate.' To tempera was to mix pigment with a binding medium in the correct proportion — not too much, not too little — so that it would adhere to a surface, dry evenly, and retain its color. Egg tempera, the dominant form of the medium in medieval and Renaissance Europe, uses egg yolk as the binder: the yolk contains lecithin, a natural emulsifier, and proteins that dry to form a hard, water-resistant film that can preserve pigment almost indefinitely. The precision required to mix the correct proportions of pigment, yolk, and water was the craft of the tempera painter.

Egg tempera was the primary painting medium of European panel painting from the Byzantine period through the fifteenth century. The altarpieces of Giotto, Duccio, Fra Angelico, and the early Flemish masters were all executed primarily in egg tempera, using thin transparent layers — each one dried completely before the next was applied — to build up form and color. The technique demanded a particular discipline: unlike oil paint, egg tempera dries rapidly (within minutes of application) and cannot be blended on the surface. The painter must pre-mix every tone they will need and apply it in small, precise strokes — hatching and crosshatching being the characteristic way of suggesting gradation, since gradation by blending is unavailable. The result, when done well, is a surface of exceptional clarity and luminosity, with colors that retain their brightness across centuries.

The transition from tempera to oil paint in the fifteenth century was one of the most consequential technical revolutions in the history of art. Oil paint — which dries slowly, can be blended on the surface, allows glazes of extraordinary depth and luminosity, and can be applied in thick physical impasto — opened possibilities that tempera's rapid drying and thin application could not offer. The Flemish painter Jan van Eyck is traditionally credited with perfecting oil paint around 1420, though the transition was gradual and the full possibilities of oil were only explored over subsequent generations. By 1500, tempera had been largely displaced for panel painting, surviving primarily in preparatory underdrawing and in mixed-technique works where tempera provided the foundation and oil the final layers.

Egg tempera experienced a significant revival in the twentieth century, particularly in America, where painters like Andrew Wyeth, Paul Cadmus, and Reginald Marsh were attracted to its luminosity, precision, and archival stability. Wyeth's temperas — most famously Christina's World (1948) — exploit the medium's characteristic qualities: the dry, even surface, the clarity of each strand of grass individually rendered, the absence of the physical texture that oil impasto would have introduced. Wyeth's temperas feel like accumulated looking rather than accumulated paint, and the medium's demand for patient, methodical work suited his particular way of seeing. The ancient medium, unchanged in its essentials from Duccio's altarpieces, found in mid-century American realism a new set of purposes it was ideally suited to fulfill.