Colors for Printing Inks.
The different colors, and the inks which may be made from them, are as follows:
For Red.—Orange lead, vermilion, burnt sienna, Venetian red, Indian red, lake vermilion, orange mineral, rose pink and red lead.
Yellow.—Yellow ochre, gamboge, and chromate of lead.
Blue.—Cobalt, Prussian blue, indigo, Antwerp blue, Chinese blue, French ultramarine, and German ultramarine.
Green.—Verdigris, green verditer, and mixtures of blue and yellow.
Purple.—A mixture of those used for red and blue.
Deep Brown.—Burnt umber, with a little scarlet lake.
Pale Brown.—Burnt sienna; a rich shade is obtained by using a little scarlet lake.
Lilac.—Cobalt blue, with a little carmine added.
Pale Lilac.—Carmine, with a little cobalt blue.
Amber.—Pale chrome, with a little carmine.
Pink.—Carmine or crimson lake.
Shades and Tints.—A bright red is best got from pale vermilion, with a little carmine added; dark vermilion, when mixed with the varnish, produces a dull color. Orange lead and vermilion ground together also produce a very bright tint, and one that is more permanent than an entire vermilion color. The pigments are dear; when a cheap job is in hand, orange mineral, rose pink and red lead may be used.
Yellow.—Of the materials named, the chromate of lead makes the brightest color. If a dull yellow be wanted, yellow ochre may be used; it grinds easily and is very cheap.
Blue.—Indigo is excessively dark, and requires a good deal of trouble to lighten it. It makes a fine, showy color where brightness is not required. Prussian blue is useful, but it must be thoroughly ground. It dries very quickly, hence the roller must be frequently cleaned. Antwerp blue is very light and easily worked. Chinese blue is also available. As already said, the shade may be varied with flake white. There is this objection to Prussian, Antwerp, and Chinese blues, that they are hard to grind, and likely to turn greenish with varnish when used thin. A bright blue is also to be got from cobalt, or French or German ultramarine. This is cheap, easily ground, and works freely. Lime blue may also be used.
Green.—Any of the yellows and blues may be mixed. Gamboge, a transparent color, is very useful in mixture with Prussian blue; or chromate of lead and Prussian blue may be used. The varnish, having a yellow tinge, has an effect upon the mixture, and should be taken into account. With a slight quantity of Antwerp blue, varnish in itself will produce a decidedly greenish tint. Verdigris and green verditer also give greens. If Chinese blue be added to pale chrome, it gives a good green, and any shade can be obtained by increasing or diminishing either color. Emerald green is got by mixing pale chrome with a little Chinese blue, and then adding the emerald until the tint is satisfactory.
Brown.—Sepia gives a nice tint, and burnt umber a very hot tint. Raw umber gives a brighter brown, bistre a brighter still.
Neutral tints are obtained by mixing Prussian blue, lake and gamboge.
In using painters’ colors, it is advisable to avoid, as much as possible, the heavy ones.
Tints of any desired depth may be made by using a finely-ground white ink as a basis, and toning it with the color desired.
Varnish tints are made by adding color to full-bodied, well-boiled printers’ varnish, using a little soap and drying preparation to make them work smoothly and dry quickly.
In mixing tints to print with, the muller should be used to rub in the colors thoroughly, otherwise the work is liable to be streaky. It is advisable to mix no more of a tint than is needed for the work in hand. Most colored inks work best if applied to the rollers a little at a time, until the depth of color desired is reached, as colored inks distribute slower than black, and are more liable to thicken upon and clog the type when too much is taken at once.