CHAp XIII.
Of colouring or waftiing maps, prints,
&fc.
THE colouring maps, or other prints, is
performed, either by Ipreading opak*
colours fo thinly on the fubjedt, that the full
cffedt of the printing may appear under themj
or by uiing tranfparent colours, which llain the
ground and dry away without leaving any
opake body: this laft method is called wajhing.
The uiing opake colours, or fuch as have a folid body, in this way on prints, depends in* tirely on the kind of vehicle ufed. For if the colour be fufpended by the vehicle, that it can be fpread fo as to lie in the moll fparfed, and yet equal manner, it may be applied to this purpofe with fuccefs : and fuch as are very ftrong and bright, even though of the moft opake body, as vermilion, verditer, ultramarine, or turpeth mineral, will anfwer the end. The bell method of doing this is the uiing the ifinglafs fize, as 1 before intimated, prepared with fugar or honey, according to the directions given in p. 168: which makes the colours of this fort work fo freely, that they may be dif- fufed almoft as ealily as the tranfparent kinds j and with nearly as good effedt. The proportion of the ftrength of the fize to each particular fort is likewife beforementioned in and it is therefore unneceflary to give it here : but it is proper in moft cafes to dilute the compofition more for the wafhing maps, and fpreading the colour over large furfaces, than when employed in painting.
Befides the opake, there are a number of colours, which are femi-tranfparent, and yet have a body in a greater or lefs degree ; thefe are carmine, biftre, and gall-ftone in the firft degree, with lake and Pruffian blue in the fécond ; all which may be treated in the fame manner, but require very different proportion in the ftrength of the fize ; for the firft of thefe claffes ought to have as little as poffible of the fize ; and the latter to be more copioufly fur- nifhed with it.
The tranfparent colours fhould be preferred for this purpofe to either of the other kinds ; as their effect is better, and they require no preparation. Thefe colours are, red ink ',—for blue, litmus ;—for green, fap green, and verdigrife (in vinegar \)—fcr yellow, gamboge, the yellow berry wafh and turmeric wafh ',—for purple, the logwood wafh and archal;— for brown, Spanifh liquorice;—
and for black, Indian ink. Thefe require only to be diflolved in water ; which fhould be more copioufly added where they are employed for wafhing prints or colouring large grounds of any kind.
With refpefk to the manner of ufing any of thefe claffes in the colouring maps and prints, there is nothing more required, than in any other painting; except that it muft be carefully obferved in employing the opake or femi-tranlparent colours, never to cover any parts fo ftrongly with them, as to prevent the diftindt appearance of the (hades of the printed defign j as they are to (hew them- felves through the colours j and form die (hades of the pidture made by the colouring.
In the illuminating (as it is called) maps, as little peculiar in the manner is neceffary as in the cafe of other prints: only, the intent of colouring them being to diftinguilh the divi- lions of the maps with refpedt to countries, dKindts, &c. care muft be taken not to lay the fluid colours on fo copioully as to flow beyond the limits of what they are intended to cover: and the reft depends on the difpofing of the variety of colours fo in different parts as to give them a ftrong and pleafing effedt; which muft depend more on fancy and good tafte than on any rules. There is indeed one thing in particular, which it may be proper to remark, (hould be always avoided : it is, the laying thofe colours, tnat have any affinity or like- refs, clofe to each other: for by an error in this particular, they will be rendered much left effedtual with refpedt to the purpofe they are to (erve; as.it is by fuch a dilpofition made more difficult to the eye, to diftinguilh the limits and bounds they are intended to mark ' out: and indeed, befides, for want of due ap- pofition, the diverlification of the colours is made left pleafing, when they are feen at a diftance, and confidcred only with refpedt to their ornamental appearance. There is one other rule, I will likewife recommend the ob- fervance of, though many think they are giving moft perfedtion to their work when they .moft deviate from it y it is, the never ufing too ftrong and deep colours for this purpofe j as -they render the legible characters of the maps lefs diftindt and perceptible y fuch a practice is therefore repugnant in a certain degree to the principal intention of the maps ; and moreover gives them a tawdry glaring appearance ; which is very inconfiftent with good tafte ; one great principle of which is fimplicity, and the avoiding a falie and unmeaning Ihowinefs. 1