AGLIONBY, William, Painting Illustrated in Three Diallogues. Containing some Choice Observations upon the Art. Together with The Lives of the Most Eminent Painters From Cimabue, to the time of Raphael and Michael Angelo. With an Explanation of the Difficult Terms, London, John Gain, 1685.1 quotations
I have heard, that in some Pictures of Raphael, the very Gloss of Damask, and the Softness of Velvet, with the Lustre of Gold, are so Expressed, that you would take them to be Real, and not Painted : Is not that as hard to do, as to imitate Flesh ?
No : Because those things are but the stil Life, whereas there is a Spirit in Flesh and Blood, which is hard to Represent. But a good Painter must know how to do those Things you mention, and many more : As for Example, He must know how to Imitate the Darkness of Night, the Brightness of Day, the Shining and Glittering of Armour ; the Greenness of Trees, the Dryness of Rocks. In a word, All Fruits, Flowers, Animals, Buildings, so as that they all appear Natural and Pleasing to the Eye. And he must not think as some do, that the force of Colouring consists in imploying of fine Colours, as fine lacks Ultra Marine Greens, &c. For these indeed, are fine before they are wrought, but the Painter’s Skill is to work them judiciously, and with convenience to his Subject.