Читать книгу The Mixing of Colours and Paints - F. N. Vanderwalker - Страница 14

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Vermilions.—Above in this chapter American vermilion is described. It is a basic chromate of lead and is quite a different color from English, French and Chinese vermilions, which are made of sulphur and mercury. These colors are found naturally in large quantities as the mineral cinnabar. The natural cinnabar is not brilliant enough in color, however. Most of the English vermilion is made by chemical process.

American vermilion is used mostly in the commercial arts, while English, French and Chinese vermilions are used in the fine arts and are more expensive. The latter colors seriously retard the drying of oil and also tend to turn black on exposure to the air.

American Vermilion, is commonly used where a brilliant red is needed, although a durable red of even greater brilliance for some decorative purposes can be made by toning alizarine crimson with cadmium orange.

All of the sulphide of mercury vermilions—(except American, which is a lead chromate color)—should not be mixed with white lead or such lead colors as light, lemon, medium and orange chrome yellows nor with American vermilion. The sulphur of the mercury colors causes the lead colors to darken. The mercury vermilions also cause unfavorable chemical reactions on colors from a copper base such as emerald, verdigris and malachite greens.

American vermilion was very extensively used a few years ago for painting farm machinery, but it has been displaced by the more brilliant artificial para reds made from coal tar dye and which are less expensive.

American vermilion is superior to most pigments as a protective coating for iron. It is very heavy and too expensive for general use in this manner.

Vermilionette.—Made from the coal tar dye eosine as the coloring matter for tinting an inert base like barytes. The colors range from rather pale pink to deep scarlet. These colors have been much used in automobile and carriage paints. Vermilionettes fade in sunlight.

Tuscan Red.—Rather a bright red made by toning to brighten the color of oxide of iron red—reds like Venetian and Indian—with alizarine red, which is a coal tar red. As made today it is permanent as to color, stable chemically and doesn't bleed.

Harrison Red.—A permanent bright red coal tar product. Not so brilliant as vermilion but used in place of it at times. It is more transparent than vermilion and is quite stable, mixing well with madder lakes and cadmium yellows. A slow drying pigment.

Light Red.—A very permanent red which has great tinting strength and good drying qualities. Stable chemically and mixes well with all colors. Made by roasting yellow ochre.

Magenta (Mauve).—A purple red made from coal tar dyes on an alumina base. Brilliant and beautiful but very fugitive to light. Used only for temporary work.

Mars Red.—An oxide of iron pigment similar to the ochres. Rather slow drying. Permanent in color and may be mixed with all mineral colors, but not with genuine or natural lake colors.

Scarlet Vermilion.—A sulphide of mercury vermilion similar to English, French and Chinese vermilions.

Terre Rosa.—A natural earth pigment which drys well and is permanent in color. It is stable and mixes with other colors. Chemically it is sesquioxide of iron and clay.

Scarlet Lake.—Genuine natural madder lake.

Geranium Lake.—A coal tar lake color made from eosine.

Crimson Madder.—A deep red of transparent character. Genuine madder is made from madder root. Permanent when used with good judgment only as a glaze color. Not stable when mixed with chemical colors, or ochres.

Carmine.—The lake color called French carmine is made by extracting coloring matter from cochineal insects. Vast quantities of these insects are secured from Mexico and South America. Carmine is transparent, rather a slow drying color and not permanent for long in strong light, though a most brilliant red. The insect bodies are dried, the color is extracted by boiling them in water and then precipitated on an alumina clay base. Carmine lake has been made over 200 years. This, like all lake colors, must be used over correct ground colors, since it is too transparent to hide the surface. They are strong in tinting and staining power, but have little opacity.

Pink Madder.—Similar to genuine madder lake or alizarine lake, but a lighter color.

Alizarine Crimson Lake.—One of the coal tar lakes. Transparent, permanent in color and a good drying color. A purple-red in color. Genuine or natural crimson lake is made from the same cochineal insects and in largely the same way as carmine.

Alizarine Lake.—A transparent aniline lake color of great tinting and staining ability. Quite similar to scarlet and carmine in color. Alizarine is used extensively for making fast mahogany stains and also for a glazing color by decorators in place of natural madder lake. Its greatest use is for brightening oxide of iron in making permanent Tuscan reds.

Alizarine Red.—A coal tar dye color of brilliant hue. Permanent in color and stable.

Eosine Red.—A coal tar dye used with orange mineral to make vermilions. It is fugitive to strong light.

Para Red.—One of the most extensively used of the coal tar reds. It is used alone and also mixed with orange mineral for vermilions. This para nitranaline red has remarkable opacity. One pound of it in a gallon of varnish will cover solidly in one coat and hide black. Its opacity is so great that it is commonly sold in the proportion of only 10% to 12% of color on a white inert base like barytes or whiting. And certain farm implement manufacturers specify this red to be made with 5% color, 10% zinc and 85% barytes.

The weakness of para red is its tendency to "bleed". It is soluble in oil and works its way up through varnish, enamel and paint. Sometimes shellac will seal it up and sometimes aluminum paint will seal it.

Toluidine Red.—A coal tar aniline color similar to para red but lighter in color. It does not bleed like para red and is the fastest known organic color, being quite remarkable in permanence. It is greatly used as a sign painter's red. Because its cost is much greater than that of para red, it is not used in the implement manufacturing industry.

Rose Pink.—A lake color mode from hypernic. Transparent but has an agreeable red color, good staining and tinting ability. Made quite like scarlet lake, using amanarth and acid rubine.

Rose Lake.—Similar to rose pink in manufacture but slightly different in color hue.

Rubens Madder.—Genuine natural madder lake.

Rose Dore.—Genuine natural madder lake.

Rose Carthame.—made at first from the flowers of the carthamus plant. Now made from eosine dye, a coal tar product. Not permanent as to color.

Rose Madder.—Genuine natural madder lake.

Scarlet Madder.—Genuine natural madder lake.

Madder Lake.—Made from madder root and is consequently of vegetable origin. A beautiful, transparent lake which is extensively used by artists and decorators. A deep red in color useful only for glazing. Genuine madder is quite permanent when so used.

The vegetable madder lake has been almost entirely superseded today by a color made artificially and known as alizarine lake.

Nopal Red.—This is an aniline color which is fugitive in strong light. Nopal orange has the same characteristics.

Orange Vermilion.—A yellow red similar to English, French and Chinese vermilions. A sulphide of mercury color.

Scarlet Lake.—A different color from scarlet vermilion. Scarlet lake is quite like carmine as to color. Made from scarlet acid, barium chloride, blanc fixe and soda sulphate or sulphuric acid.