(b) A fine, intensely black, strong ink, without the use of oil and rosin, may be made in the following manner :-9 oz. balsam of copaiba, 3 oz. lamp-black, 11 oz. indigo, or Prussian blue, or equal proportions of each, oz. Indian red, 3 oz. dry turpentine soap, ground between a muller and a stone to impalpable fineness. This is an excellent ink for giving good effect to highly finished wood-engravings.
B. COLOURED.—Printing-inks may be made in a number of colours besides black. The prin cipal are the following :— Red: (a) Carmine may be readily ground into a fine ink of brilliant colour by admixture with black ink varnish made with balsam of oopaiba. It is expensive, but valuable for special purposes. (b) Crimson lake is easily reduced by the muller ; .it works clean, and does not require more soap than is contained in the varnish, but it does not possess much depth. (c) A deeper tone than can be obtained from commercial lake may be produced in the following manner :-1 oz. best cochineal, powdered, and boiled in 1 qt. water, till the colouring matter is extracted ; let the cochineal subside, and pour the liquid into another vessel ; when cold, gradually add some chlorate of tin, with constant stirring, till the supernatant liquid, on standing, becomes nearly colourless ; then add a little powdered alum. Assist the solution by stirring ; allow to subside ; pour off the excess liquid ; wash the coloured residue with 3 or 4 waters, to remove the acid ; and dry carefully and slowly. The addition of cream of tartar during the process will give a purple tint. (d) Vermilion may be used for red ink where neatness is required, as for title lines of books, The quantity varies much, and necessitates care iu its proportions. It requires much soap to make it work clean. (e) For cheap work, such as postjng-bills, red-lead may be used ; it requires additional soap to make it work clean, and its colour soon changes to black. (f) An excellent, permanent red, of rich tone, may be produced from Indian red. (g) Venetian red is easily ground into a smooth ink, and requires but little more soap than the varnish usually contains ; it is not very intense.
Yellow: (a) The highest yellow is obtained from chromate of lead, which is easily ground into a fine ink, works freely and well, and requires hut little soap beyond what the varnish contains.
(b) Yellow ochre is easily ground into a fine ink ; it gives a useful colour, dull but permanent.
Green : Various shades of green may be produced by suitable admixture of blues and yellows. Prussian blue and chromate of lead make a good rich green; indigo and the same yellow, a deeper, duller colour ; Antwerp blue and the same yellow, a brilliant rich green. The chromate must be quite pure to ensure bright colours.
Blue : (a) Indigo gives a deep but dull blue; it is cold, but permanent. (b) Prussian blue needs much grinding, and extra soap ; it affords a deep, bright colour, and is useful for making greens. (c) Antwerp blue is easily ground to the proper degree of fineness, makes a good ink, and works clean and well; its tint is bright and light, with a slight green tendency.
Purple: Different shades of purple may be made by grinding together carmine, or purple lake, with Prussian blue.
Engraving-inks.—Under the term "engraving-inks," will be included all inks employed for engravers' purposes, whether on stone, wood, or metal.
BLACK.—(a) Coal-tar, 100 parts ; lamp-black, 36 ; Prussian blue, 10 ; glycerine, 10. This ink may he used for lithography, chromolithography, autography, &c. (b) To the varnish obtained by boiling linseed-oil, as for printing-ink, is added as much best calcined Paris black as can be ground up with it. This is a litho printing-ink. For copper-plate printing, the Paris black is replaced by lamp-black. (c) 8 oz. mastic in tears, 12 oz. shellac, 1 oz. Venice turpentine ; melt together ; add. 1 lb. wax, 6 oz. tallow ; when they are dissolved, add 6 oz. hard tallow soap-shavings, and mix ; then add 4 oz. lamp-black. Mix all well together, let cool slightly, pour into moulds, and out into cakes of convenient size. This ink is suited for writing on stones. (d) To render (c) liquid, for writing and drawing ou transfer-paper, it is warmed in a pot, and then rubbed down with soft water (rain, or distilled water). The pen should be dipped into oil, and wiped, before use.