'PARTI.
OF THE
MAtERIA PICTORIA:
OR,
The nature, preparation, and ufe of all the Various fubflances employed in painting.
C H A P. I.
Of the fubflances in general ufed in
painting.
T
H E principal kind of fubflances ufed in painting is the COLO UR S : by which, is to be underflood, all the various bodies employed by painters, for pro-
ducing the difference of hue or teint: but, as feveral of. thefe are of a fblid confiflence, and an earthy, or incohering texture, it was necef-fary, as well for the laying them on, and fpreading them properly, as for the binding and making them adhere to the grounds on which they are laid, that, in many cafes, fomewhat of a fluid natue fhould be added to give them an undtuous confiflence while ufed, and proper degree of tenacity when again dry:
B and,
2 OF THE SUBSTANCE«
and, to this end, many different kinds of bo-* dies have been applied; from whence proper VEHICLES hare been formed, which, at'the fame time, anfwer the double purpofe of reducing the colours to a ftate fit for tneir being worked with the brulh or pencil, and of cementing them to each other and the ground they are laid upon; as alfo of defending diem from being eafily injured by accidents.
The fubftances ufed in painting may be therefore all confidered as of thefe two kinds; Colours and Vehicles. For, though there arc feveral ufed occafionally, which are not immediately fubfervient to the principal intentions of vehicles; yet, being employed to remedy the defefts of thole which are, they mull be cohfi- dered as lubordinate to them; and ought, con- fequently, to be clafied with fuch as compofe vehicles.
The nature of thefe fecondary intentions, I fhall, therefore, point out in its due place; and reduce die fubftances ferving to them to their proper dalles accordingly: as it is necef- Jary, m order to underftand critically and completely the art of preparing and ufing the various arricies of the materia pi&oria, to comprehend dearly the general intention in which each is ufed, as well as to know the particular purpofe to which it is applied. And* for the fame reafbn, as alio for the lake ofbeing intelligibly concife, I ihall treat of the whole under fuch methodical diftindtions as refer to thefe intentions.: adopting, neverthdefe, on
every
Oétaflon, die terms of art in comrhoil Ufe ; afid explaining them, according to the meaning they bear when applied with any propriety or precifion, by the particular relation they have to thefe intentions«