# Egg Tempera and Oil: What Each Medium Can Do > Oil did not replace tempera because anyone invented it. Each medium sets a hard limit on what a painter can do, and both limits are legible on the finished surface. > The Study - 2026-08-02 > Canonical HTML: https://iconotheca.com/study/egg-tempera-and-oil-what-each-medium-can-do/ ## Key points - The oldest known oil paintings are mid-seventh-century Buddhist murals at Bamiyan, and Theophilus described oil paint in Europe around 1125. - Egg tempera sets in seconds, so tone is built by hatching; it cannot be blended wet and it cannot carry deep saturation. - Oil's slow oxidative drying is the whole advantage, and its cost is yellowing, darkening and increasing transparency with age. - Vasari's claim that Antonello da Messina brought oil painting to Italy is not supported; his contribution was mastery of a technique already present. ## Nobody invented oil painting, and the origin story is a catalogue hazard ## What egg does to pigment, and what it refuses to do ## Oil bought time, and time bought tone ## The transition was a slow mixture, and dating a picture by its medium is a trap ## How to read the difference off the surface Medium is not a stylistic preference that painters exercised freely. Egg sets in seconds and forces a picture to be assembled out of strokes; oil cures over days and lets a picture be blended, glazed and revised. Everything else - the hatching, the depth of the darks, the fused shadow, the drying crack, the ghost of a moved hand - follows from those two facts about drying. A specialist who knows what each binder physically permits can look at a surface and say what it cannot be, which is a stronger position than any connoisseurial impression of quality. ## Questions **Can binder analysis distinguish egg tempera from oil reliably?** Yes, in principle: proteinaceous and lipid binders have distinct signatures, and the standard laboratory techniques separate them on a micro-sample. The complication is mixtures, since tempera grassa and oil-over-tempera layer structures are period practice, so the useful question is which binder is in which layer rather than which binder the picture is. **Why do tempera paintings look better preserved than older oils?** Because the medium is optically stable. Tempera colours change little over time, while oil films yellow, darken and become more transparent, so an oil picture drifts away from its original tonal relationships in a way a tempera picture does not. Condition of the support and the ground is a separate question, and there tempera's brittle gesso is the more vulnerable system. **Does the presence of oil in a fifteenth-century Italian panel indicate a later intervention?** Not by itself. Oil was known in Europe from at least the twelfth century and was in experimental use in Italian workshops well before 1500, alongside tempera and in mixed emulsions. What would indicate intervention is oil sitting above an aged varnish or filling losses, which is a stratigraphy question rather than a medium question. **Did Antonello da Messina introduce oil painting to Italy?** The claim comes from Vasari and is now regarded as wrong. Antonello most likely encountered the technique through Netherlandish pictures circulating in Naples and Sicily and through contact with Petrus Christus around 1456. His importance is that he demonstrated what the medium could do at a level that made the advantages unarguable. ## Sources - [1] Wikipedia, 'Tempera': yolk emulsion and dilution, hatching, curing time of three to six months, colour stability, tempera grassa, chronology of displacement by oil. Tertiary source; replace with conservation-science literature. - [2] Wikipedia, 'Oil painting': Bamiyan c. 650 AD, Theophilus c. 1125, drying oils and yellowing, fat over lean, glazing over light grounds, displacement of tempera by about 1540. Tertiary source. - [3] ScienceDaily / European Synchrotron Radiation Facility, 'Ancient Buddhist Paintings From Bamiyan Were Made Of Oil', reporting results published in the Journal of Analytical Atomic Spectrometry, 22 April 2008. - [4] Wikipedia, 'Antonello da Messina': Vasari's claim and the modern view, dates, Petrus Christus, Venetian period 1475-76. Tertiary source. - [5] Wikipedia, 'Cennino Cennini': dating of Il Libro dell'Arte to the 1390s, four surviving manuscripts, first publication by Tambroni, Rome 1821. Tertiary source. - [6] Tate, 'Tempera' (art term): definition as pigment bound in a water-soluble emulsion, applied to a rigid support. - [7] Wikipedia, 'The Mocking of Christ (Cimabue)': egg tempera and gold leaf on gesso-prepared poplar, dimensions. Tertiary source; replace with the Louvre acquisition file. - [8] Wikipedia, 'Panel painting': transition from panel to canvas in Italy and the Netherlands, Rubens's Het Steen (1636) built from eighteen panels. Tertiary source.