BROWNE, Alexander, Ars Pictoria : or an Academy Treating of Drawing, Painting, Limning, Etching. To which are Added XXXI. Copper Plates, Expressing the Choicest, Nearest, and Most Exact Grounds and Rules of Symmetry. Collected out of the most Eminent Italian, German, and Netherland Authors. By Alexander Browne, Practitioner in the Art of Limning. The Second Edition, Corrected and Enlarged by the Author, London, Arthur Tooker - William Battersby, 1675.1 quotations
Now the Painter expresseth two things with his colour : First the colour of the thing, whether it be artificial or natural, which he doth with the like colour, as the colour of a blew garment with artificial blew, or the green colour of a Tree with the like green : Secondly he expresseth the light of the Sun, or any other bright Body apt to lighten or manifest the colours, and because colour cannot be seen without light, being nothing else (as the Philosophers teach) but the extream Superficies of a dark untransparent Body lightned, I hold it expedient for him that will prove exquisite in the use thereof, to be most diligent in searching out the effects of light, when it enlightneth colour, which who so doth seriously consider, shall express all those effects with an admirable Grace ; […].
Now when the Painter would imitate this blew thus lightned, he shall take his artificial blew colour, counterfeiting therewith the blew of the garment, but when he would express the light, wherewith the blew seems clearer, he must mix so much white with his blew, as he findeth light in that part of the garment, where the light striketh with greater force, considering afterwards the other part of the garment, where there is not so much light, and shall mingle less white with his blew proportionably, and so shall he proceed with the like discretion in all the other parts : and where the light falleth not so vehemently, but only by reflexion there he shall mix so much shadow with his blew, as shall seem sufficient to represent that light, loosing it self as it were by degrees, provided alwayes, that where the light is less darkned, there he place his shadow,
In which judicious expressing of the effects of light together with the colours, Raphael Urbine, Leonard Vincent, Antonius de Coreggio and Titian were most admirable, handling them with so great discretion and judgement, that their Pictures seemed rather natural, then artificial ; the reason whereof the vulgar Eye cannot conceive, notwithstanding these excellent Masters expressed their chiefest art therein, considering with themselves that the light falling upon the flesh caused these and such like effects, in which kind Titan excelled the rest, who as well to shew his great Skill therein, as to merit commendation, used to cozen and deceive Mens Eyes, […].