Flanders BLUE is a colour bordering on green, and seldom used but in landscapes.
To write on paper or parchment with BLUE ink. Grind blue with honey, then temper it with glair of eggs, or gum made of isinglass.
BLUEING of metals is performed by heating them in the fire, till they assume a blue colour; particularly practised 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 solution of alum-water, and wet the skins in the same manner once or twice; dry them, and they will be very blue.
Dyers BLUE is one of their simple or mother-colours, used in the composition of others. It is made of woad, indigo, and a pastel brought from Normandy. Some dyers heighten their blue, by adding Brasil and other woods.
A BLUE for painting or staining of glass. Take fine white sand twelve ounces, zaffer and minium of each three ounces; reduce them to a fine powder in a bell-metal mortar; then putting the power into a very strong crucible, cover it and lute it well, and, being dry, calcine it over a quick fire for an hour; take out the matter and pound it; then to sixteen ounces of this powder add fourteen of nitre powder; mix them well together, and put them into the crucible again; cover and lute it, and calcine for two hours on a very strong fire.
Prussian BLUE. This blue is next to ultramarine for beauty, if it be used in oil: This colour does not grind well in water.
BLUE bice is a colour of good brightness, next to Prussian blue; and also a colour of a body, and will flow pretty well in the pencil.
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 itself a pleasant blue, to be laid between the light 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 is a fine blue for shading.
Indigo-BLUE. This makes the strongest shade for blues of any other, and is of a soft warm colour, when it has been well ground, and washed with gum-water, by means of a stone and a muller.
Lacmus, or Litmus BLUE. This is a beautiful blue, and will run in a pen as free as ink. It is made of lacmus, and prepared thus: Take an ounce of lacmus, and boil it in 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. This affords a beautiful colour, has extraordinary effects, and is a holding colour; if it be touched with aqua-fortis, it immediately changes to a fine crimson, little inferior to carmine.