Note 198 — Chapter VI · (XX.)

The word ‘tempera’ is used by Vasari and other writers as a noun meaning (1) a substance mixed with another, as a medium with pigments (2) a liquid in which hot steel is plunged to give it a particular molecular quality (ante, p. 30) (3) the quality thus given to the steel (ante, p. 32), while (4) it has come to mean in modern times, as in the heading of this Note, a particular kind of painting. It is really to be regarded as the imperative of the verb ‘temperare,’ which alike in Latin and in Italian means ‘to divide or proportion duly,’ ‘to qualify by mixing,’ and generally ‘to regulate’ or ‘to discipline.’ ‘Tempera’ thus means strictly ‘mix’ or ‘regulate.’ It is used in the latter sense in metallurgy, as the liquid which Vasari calls (ante, p. 30) a ‘tempera’ (translated ‘tempering-bath’) regulates the amount of hardness or elasticity required in the metal, and the quality the steel thus receives is called (ante, p. 32) its ‘temper.’ In the case of painting the ‘tempera’ is the binding material mixed with the pigment to secure its adhesion to the ground when it is dry. The painting process is, in Italian, painting ‘a tempera’ ‘with a mixture,’ and our expression ‘tempera painting’ is a loose one. For the form of the word we may compare ‘recipe,’ also employed as a substantive but really an imperative meaning ‘take.’

Strictly speaking any medium mixed with pigments makes the process one ‘a tempera.’ Many substances may be thus used, some soluble in water, as size, gum, honey, and the like; others insoluble in water, such as drying oils, varnishes, resins, etc., while the inside of an egg which is in great part oleaginous may have a place between. It is not the usage however to apply the term ‘tempera’ to drying oils or varnishes, and a distinction is always made between ‘tempera painting’ and ‘oil painting.’ See Note on ‘Tempera Painting,’ postea, p. 291.