1911 Encyclopædia Britannica/Tempera

TEMPERA (the Italian term), or Distemper, a method of painting in which solid pigments are employed, mixed with a water medium^[1] in which some kind of gum or gelatinous substance is dissolved to prevent the colours from scaling off. Tempera is also called in Italy fresco a secco, as distinguished from fresco buono, or true fresco, painted on freshly laid patches of stucco. Various media have been used for tempera work, such as the glutinous sap of the fig and other trees, various gums which are soluble in water, and size made by boiling down fish-bones, parchment and animals' hoofs. A mixture of egg and vinegar has also been found to make a good medium, especially when it is desirable to apply the colours in considerable body or impasto. For the nature and history of painting in tempera and fresco, see Painting.

1. Hence it used to be called “ water-work "; see Shakespeare, Hen. IV., part ii. act ii. sc. 1.