Dictionarium Polygraphicum. Blue.

Dictionarium Polygraphicum:
Or, The Whole Body of Arts Regularly Digested.
Vol I.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV.
1735BLUE is one of the primitive colours, otherwise call’d Azure.

Painters Blue is made different, according to the different kinds of painting.

In limning, fresco, and miniature, they use indifferently ultramarine, blue ashes, and smalt; these are their natural Blues, excepting the last, which is partly natural, and partly artificial.

In oil and miniature they also use indigo prepared: see INDIGO. As also a factitious ULTRAMARINE, which see.

Enamellers and painters upon glass have Blues proper to themselves, each preparing them after their own manner.

Turnsole BLUE is a Blue us'd in painting on wood, made of the seed of that plant. The way of preparing it is to boil four ounces of Turnsole in a pint and half of water, in which lime has been slack'd.

Flanders BLUE is a colour bordering on green, and seldom us’d but in landskips.


To write on paper or parchment with BLUE ink.
Grind Blue with honey, then temper it with glair of eggs or gum water made of ising-glass.


BLUEING of metals, is perform'd by heating them in the fire till they assume a Blue colour; particularly practis'd by gilders, who blue their metals before they apply the gold and silver leaf.


To dye skins BLUE.
Boil elder-berries or dwarf-elder, then smear, and wash the skins therewith, and wring them out; then boil the berries as before in a dissolution of alum water, and wet the skins in the same manner once or twice, dry them, and they will be very blue.

Another way to dye skins BLUE.
Steep the best indigo in urine for a day, then boil it with alum, and it will be good; or temper the indigo with red wine, and wash the skins therewith.


The Prussian BLUE.
This Blue is next to ultramarine for beauty, if it be used in oil; tho’ I am not certain whether it will hold so well as the other, confidering it has not the body of ultramarine.
This colour'd does not grind well in water; because there is such an oily quality in it, that it does not mix kindly with water, and at the best will change, as it is now prepared in the common way.
Attempts have been made to make of it a blue ink; which indeed has held the colour for a month or two, but then turn'd to a muddy yellow.
And when you put your pencil with gum water into a shell of this Blue, you will find where the water spreads, the Blue will change yellowish, till the body of the Blue is well stirred up.
And after all that can be done with this colour in water, it will only serve to shade ultramarine with; but in oil it will serve very well for the present to supply the place of ultramarine.

BLUE BICE is a colour of a good brightness next to Prussian Blue, and also a colour of a body, and will flow pretty well in the pencil; especially if it be well wash'd, as is directed to be done of the whites and minium.

Saunders BLUE is also of very good use, and may serve as a shade to ultramarine, or the blue bice, where the shades are not required to be very deep; and is of it self a pleasant Blue, to be laid between the lights and shades of such a flower, as is of a mazarine Blue.


A fine BLUE from Mr. Boyle.
Take the blue leaves of rue, and beat them a little in a stone mortar, with a wooden pestle; then put them in water, juice and all, for fourteen days or more, washing them every day till they are rotten; and at last beat them and the water together, till they become a pulp, and let them dry in the sun.
This will produce as good a Blue as indigo, and be much foster; but in order to keep it a long time, when you beat it the last time, add to it a little powder of gum Arabick; of which you may put more or less, as you would have it more free or tenacious in the working.
This is a fine blue for shading, has a good body, and runs warm in the pencil.


INDIGO BLUE.
This makes the strongest shade for Blues of any other, and is a soft warm colour, when it has been well ground and wash'd, with gum water, by means of a stone and muller.
It is made of what lightness you please, by putting more m water to it; and by how much there is less, the darker it will be.
Before you use it upon a print, it will be proper to try it upon a Dutch tile, for it runs warmly in the pencil, and so perhaps may otherwise prove too strong for your design, which is always to be taken care of, when a flowing colour is to be laid over a dark shade of a print; which shade will much heighten its blackness, and even make it appear quite black.


LACMUS or LITMUS BLUE.
This is a beautiful blue and will run in a pen as free as ink. It is made of lacmus, or as some call it Litmus, which may be had at the druggists.
But as this colour is never to be met with prepar’d, I shall here set down the method of preparing it.
Take an ounce of Lacmus, and boil it in about a pint of small beer wort, till the colour is as strong as you would have it; then pour off the liquor into a gallipot, and let it cool for use; it will soon become a jelly, and by degrees grow hard.
But this colour is to be opened again, and made liquid by water, so as to be us’d as ink; and will be either paler or darker, as it is made thicker or thinner.
This affords a bright colour, and has extraordinary effects; for it is not only a beautiful, but a holding colour.
This colour if it be touch'd with aqua fortis, immediately changes to a fine crimson, little inferior to carmine, and sinks guite through the paper, so as not to be got out.
So that when this colour is us'd as blue, it is best to preserve it from aqua fortis, or such strong acids.
It is a good shade for ultramarine, or blue bice, where the strongest shades should not be extremely deep; and for colouring of prints it is very good, as it is a transparent colour, and goes a great way.