either oil, japan, varnish, or distemper; in distemper,
however, all are less permanent than they are in the other
vehicles, as these protect them.
Certain of the proprietary reds used in coach work are
remarkably well-made goods, and but for the impropriety
126 MODERN PIGMENTS
of giving some of these a free advertisement, and also of
doing sundry others, probably as good, an injustice by
not also naming them the author does not claim to
have tested them all therefore he refrains from nam-
ing any. The mention of their existence is sufficient,
because the reader is made aware of their character.
Properties and Uses
Some few decorators and artists still cling to this lake,
but there are no good reasons why its use should not be
abandoned altogether. It is universally admitted to be
very inferior to the madder lakes, but it is somewhat
more permanent than the cochineal lakes, and that
is probably why some continue its use. The excuse
is a very lame one. It is far less brilliant than and
very much inferior in durability to the madder lakes of
Indian lake is a lac of a resinous character produced
by various plants in the East Indies. These are punc-
tured by the larva of the Coccus Lacca, and the result
of the puncture is the resinous lac, from which the
color is derived. It varies in color according to the
plant from whence it is derived. This resin is pounded
in water, the water becomes red, and after having
been boiled down, the residue made by the evaporation
is the crude lac dye. This is dried and made into
cakes. The above suffices to indicate its provenance
Its use is lessening daily, and it is only a question of
time when it, as well as many other pigments which
have been useful in the past, for want of better, will
be known no more, except in history.
RED PIGMENTS 127
CARMINE AND COCHINEAL.
History and Production
Carmine is said to have been discovered by a Florentine
monk, who, while he was engaged in the preparation of
some medicine in which cochineal was introduced,
observed a bright red precipitate. For the sale of this
red, his monastery afterwards became famous.
Carmine is a coloring principle found in the body of a
small insect called cochineal. It is said that the water
used in its manufacture has a great deal to do with the
beauty and brilliancy of the pigment obtained from it.
Otherwise its extraction is a simple affair.
The following will explain in a few words how it is
extracted. Take one pound of powdered cochineal, and
add four or five drams of subcarbonate of soda or
potash. When this has been boiled in soft water for a
quarter of an hour, add eight or ten drams of alum.
After the solution has been effected, take the receptacle
from the fire, draw it off into clean vessels, and after it
has stood for about a week, the carmine will be found
deposited at the bottom. This deposit must be carefully
dried, and then it is ready for use.
There are many other methods of extracting carmine,
but the above is as simple as any, and will suffice.
Properties and Uses
Carmine is a very brilliant color when well made.
Alas! it cannot long resist the action of a strong light,
and it will quickly fade away if so exposed. Its place
is being rapidly taken by the madder lakes, and while it
must be admitted that these are not so brilliant at the
start, in a very few days they appear the more brilliant
of the two.
128 MODERN PIGMENTS
It is very rich as a glazing color over English vermilion,
and is still used for that purpose by the carriage painters,
although even for that purpose many of them have sub-
stituted a madder lake of similar tone, as most individuals
prefer a mediocre stability to a short-lived brilliancy.
It is a pity that such a fine red should be so fugitive,
and for that reason painters who value their reputations
must go slow about its use, and had better let it alone.
There are many other reds that can be found listed in
artists' supply store catalogues, but many of these can be
placed and belong to the reds described, and the rest are
for use in padding the lists; most of them are absolutely
useless even to decorators and artists. Red ochers are
sold under that name and a dozen others. They are
natural reds, the same as the yellow ochers. All such
should be, and in fact are, most advantageously displaced
by the artificially made Venetian reds, as these are uni-
form, and have the color better fixed than the natural
ocher reds, and possess the same range of color tones.
There is no object in retaining the former; they cumber
the red list uselessly. Many are little better than mortar
colors, and are decidedly poor in working qualities.
CHROME GREEN is the one green which is most used by
house painters and decorators, and for this reason it is
given first place here. It has been the aim to notice the
various pigments in a group according to prominence.
It is not possible to do this in every instance. Frequently
it is hard to choose between two which seem to have
equal claims for prominence. In this instance, it is
regrettable that there is no better one to head the list.
Chemistry and Preparation
Chrome green is a compound pigment, not only in the
sense of many other pigments of various substances com-
bined together, but also, in that it is a secondary color;
in other words, that it is of two other distinct colors which
when combined form greens, viz., Prussian blue and
chrome yellow. It can 'be made by a simple mixture
and triturating the pair.
In color works it is never so made. In these estab-
lishments they take the equivalents in chemicals of both
these colors and dissolve into solutions. Then they mix
these together in large vats, and the green is precipitated.
This green is what is known as chrome green in the United
States. By this process, it is claimed that the color thus
produced is more intimately mixed and incorporated.
Besides, it gives every manufacturer room to make the
130 MODERN PIGMENTS
claim that by his particular method of handling and pre-
cipitating, he is able to fix the coloring matter much
better than any other maker has ever been able to do,
and also claim superior permanency for the same reason.
Be that as it may, there is one sure thing, and that is,
that certain chrome greens are certainly much more
permanent than others. Some retain their tone much
longer than others, remaining of a decided green after
others of equal strength of coloring matter have badly
faded. A number seem to fade very soon after applica-
tion; others again, like some widows, wait a reasonable
time before changing their dresses.
After the chrome has been precipitated, the supernatant
water is drawn off; the pulp green is put into filtering
cloths and in presses to free it of water. The pressed
cakes are taken to the drying room and left there until
bone dry, after which they are taken out, broken up and
pulverized in the mills, and are then ready for sale as dry
chrome green; or for grinding, in oil, japan, varnish, or
water, for the various purposes for which it is adapted
What has been written above, applies to the manu-
facture of pure chrome greens; but pure chrome greens
are seldom found in the market.
Owing to their great covering properties, and amount
as well as strength of coloring matter, and their great
opacity, there is really no absolute necessity for their
absolute purity. The reason for this is that green is
seldom employed for the making of tints, as are most other
colored pigments. Green is used mostly as color by itself
for the solid painting of blinds for windows, wagon beds,
implements, iron fences, etc. A chrome green contain-
ing only 20 to 25 per cent of actual chrome green, when
it has been properly prepared upon a good base, will
GREEN PIGMENTS 131
cover solidly in one coat any other color over which it is
painted, be it black or white. It would be a waste, there-
fore, to use 100 per cent of color chrome green to do what
20 per cent of it will do as well. The 100 per cent green
might possibly cover a trifle more, as it could be thinned
more; but as no one cares to apply too thin a color, even
that would not amount to anything, and the assertion
can safely be made that one pound of 20 per cent green
will cover as much as one pound of 100 per cent.
Therefore by common consent all color manufacturers
put out a chrome green containing three parts of base to
one part of chrome green. This mixture then contains
25 per cent of absolutely pure chrome green.
The base, of whatever nature it may be or in whatever
proportion it is used, is always added to the chemical
solutions just at the moment of their being thrown into
the vats and before the color is precipitated. The base
and the color are precipitated together. This insures
Nearly all the chrome greens are sold under some pro-
prietary name, such as Crylight, Marseilles, Sylvan,
Emerald, French Imperial, and a host of others entirely
too numerous to mention; but whatever their name may
be, they are all reduced chrome greens and belong to the
class just described. None contain over 25 per cent of
actual color in their composition.
When chrome green is used for the purpose of making
tints with other pigments, either white or colored, the
strictly pure greens should be used, because there they are
the more economical. Such greens can be bought, but
they are in little demand aside from printing-ink manu-
facturers, etc. Many painters make pea greens, olives,
and the various light-toned tints of those and other greens
from ocher chrome yellows, Prussian blues, etc., which
132 MODERN PIGMENTS
they compound without the use of any chrome green.
Hence the pure greens are not always to be found at
paint supply stores, because the demand for them is very
All manufacturers do not use the same base for the
purpose of reducing the pure chrome green to the com-
mercial basis of 25 per cent, and this of itself accounts for
the difference found in their working qualities. Barytes
is that which is most commonly used for the purpose,
either alone or in conjunction with others. Gypsum
makes the best base for that purpose, as it seems to hold
up the color better, and it also works better under the
brush. Whiting is used extensively also; and added to
either barytes or gypsum to make the paste smoother
in texture, it also helps out in the better brushing out of
Properties and Uses
Chrome greens come in two tones; and accordingly as
it approaches to one or the other of these two, the green
is so classed. The two tones are known as the blue greens
and its opposite the yellow greens. In some of its blue
shades, chrome green approaches somewhat to the tone
of the Paris or emerald green. There is a wide range
to be found in the tones between a very pale yellow green
and a very deep blue green which covers the whole
gamut and chromatic scale of the green tones. Each of
these two groups of green has some uses to which it is
better adapted than the other. As a rule, the yellow-
toned greens are stronger in coloring matter than those
of a corresponding depth in the bluish ones.
One peculiarity that belongs to all chrome greens, but
in a much stronger degree in the blue than in the yellow
ones, is that no matter how carefully they may have
GREEN PIGMENTS 133
been made, if there is any supernatant linseed oil when
a can of chrome yellow is cut open the oil shows up
tinted with blue as if the blue had separated from the
yellow. This property is inherent and does not hurt it.
The necessary trituration of the color before using it will
remedy this condition and reincorporate the trifling
amount of dissolved Prussian blue.
Some of the well-made chrome greens are fairly per-
manent ; but ; as any one may well surmise, anything that
would destroy the color of Prussian blue such as lime
or other caustic substances will also destroy that color
in the chrome green combination. Sulphureted-hydro-
gen gases which affect chrome yellow, will in the same
manner destroy the color of chrome yellow in the com-
position of the green. So these greens have to carry a
double load of liability to being injuriously acted upon.
Notwithstanding that chrome green is anything but
absolutely permanent, to all intents and purposes it is
sufficiently so, that, for want of a better, it may be fairly
depended upon for many situations and certain condi-
It is used by all classes of painters, in oil, in japan or
varnish, and in enameling or japanning works. It is
also very useful in distemper work if care is taken in
mixing it that none of its incompatibles be compounded,
or it would then surely fail.
In whatever vehicle it is used, it is contra-indicated
if it is subject to any of the influences which would act
injuriously upon either chrome yellow or Prussian blue
as under the heading of either of those colors, this is
fully given, and it is unnecessary to repeat it here.
Chrome green and all the proprietary greens which,
as we have seen, are all chrome greens come in several
shades. Manufacturers pack it up in cans as: Extra
134 MODERN PIGMENTS
Light, Light, Medium, Dark, or Extra Dark, each of which
makes an entirely distinct set of tints with a white base.
To ascertain the value of a chrome green, it is proper
to make a scale test of it alongside one of the same grade
that is of known standard. With that test one can
readily determine the amount of coloring matter it
One should never take a strictly pure green to judge
values, and expect one of only 25 per cent of claimed and
acknowledged purity to come up to it. If, however, four
times as much of the commercial grade is taken as is of
the strictly pure, the tints made should be equal.
The reader will find full directions of how to make these
tests at the end of Chapter VI under the heading Chrome
GREEN OXIDE OF CHROMIUM
Properties and Uses
The green oxide of chromium is known to the artists
and decorators of the world under many names, and in
reality is the only green entitled to the name of chrome
green, for it is that. But what we know under that name
in the United States is a different pigment, which, while it
is not entitled to it, is the only one here known by that
Life is too short to start a crusade and to make a
quixotic fight against windmills which it would be if
the effort were made to change the name and it is simply
accepted through sheer compulsion; it cannot be helped.
Green oxide of chromium is a good enough name if it is
a bit long in the saying; as it is, it is so seldom used that
it matters but little anyway. Many of the proprietors
of paint supply stores would be puzzled if one was to
call for it, and would not know what was meant.
GREEN PIGMENTS 135
Owing to its limited use, but little need be said of its
manufacture. The intricate processes of manufacture
make it an expensive pigment, and that alone will always
prevent its use, even if it possessed much better qualities
than those which are inherent in it. So that with the
cheap imitation chrome greens, which cover better and
cost ever so much less, there is little danger of it ever
coming into popular use.
Two distinct processes are used in its manufacture,
and these are known as the dry and the wet. Accordingly
as it is made by the wet or the dry process, this pigment
is either transparent or opaque. The latter is the usual
condition under which it is to be found in artists' tube
colors. When made by the wet process the sesquioxide
is thrown down, and that makes it transparent. It is
therefore useful both as a solid color for opaque paint-
ing, or the transparent for glazing purposes. This pig-
ment is somewhat more permanent than the so-called
American chrome green goods which are known and sold
here as chrome green, and it can be mixed with most of
the permanent pigments.
COBALT GREEN (ZINC GREEN)
Properties and Uses
This valuable pigment deserves a more extensive
use than that which it has so far received in the United
States. In Europe, especially in England, France, and
Germany, it is much more popular than it is here. In
America, it is mainly found in tubes for artists' use, and
is seldom ever offered in any other shape. It is imported,
and if manufactured in the United States the author has
never heard of it. There is no reason why it should not
be made here. As I am not familiar with its preparation,
136 MODERN PIGMENTS
I give the following extract from Church's "Chemistry of
"It has long been known that the oxide or a salt of
zinc moistened with a solution of cobalt nitrate and then
strongly heated before the blowpipe gives a porous mass of
a beautiful green hue. This compound or mixture of the
oxides of zinc and cobalt may be prepared by: 1st.
Precipitating with an alkaline carbonate a mixture of the
nitrates of cobalt and zinc, and then strongly heating
(after washing) the precipitate formed thereby; 2d,
Making a paste of zinc oxide and water, and adding a
solution of nitrate or sulphate of cobalt or roseo-cobaltic
chloride; the mass is then dried, calcined at a dull red heat,
thrown into water, ground, washed and dried. Method
No. 2 gives a finely colored product, the depth of hue
being proportional to the percentage of cobalt ic oxide.
If the latter oxide amounts to one third that of zinc, the
color is a very deep bluish green; with no more than one
sixth, the color is still rich. Some specimens do not con-
tain more than one twentieth, occasionally even less
of cobalt oxide, and yet they are far from pale. An
excellent deep sample contained 12 per cent of cobalt
"When properly made, cobalt green is a pigment of
great beauty and power. The deeper tones of cobalt green
are almost transparent in oil. The pigment works well,
is quite permanent, and has no action upon other pig-
ments. Cobalt green is, in fact, one of the two rare pig-
ments which are at once, chemically and artistically
perfect. It must be admitted that it is almost exactly
imitated by a mixture of viridian and artificial ultramarine
with a little zinc white.
"Cobalt green is again coming into artistic use, as it is
equally well adapted for all methods of painting. It
GREEN PIGMENTS 137
was discredited awhile by the inferiority of the product
obtained by Rinmann's original process (No. 1 above)."
It ought not to be an expensive pigment, and if manu-
factured here upon a large scale its cost would be low
enough for use in general painting.
Sometimes the green is prepared by precipitating a
cobalt salt with an alkaline arseniate or phosphate, and
then heating the precipitate with zinc white.
Cobalt green, as was seen above, is more or less trans-
parent according to its depth of tone. The lighter tones
are much more opaque, and these would be the best for
solid painting, but the deep ones used as a glazing coat
over other greens give rich effects. This pigment is good
in any of the usual vehicles, and it is hoped it will become
better known to the general trade. It would be invaluable
to the carriage and car trade; and decorators should use
it more in interiors, where it is free from attacks of the
deadly enemies of most other greens,
Properties and Uses
Again recourse is had to the same source for informa-
tion concerning viridian. Church says of it:
"About eight parts of crystallized boracic acid and
three parts of potassium bichromate are thoroughly
mixed and calcined. The mass so obtained is treated with
cold water and washed by decantation, ground wet,
washed with hot water and carefully dried. The
product is an hydrated chromium sesquioxide in
which a variable amount of the boracic constituent
frequently remains. Viridian, however, is essentially
an hydrated sesquioxide of chromium, having the
formula of Cr 2 3 2H 2 O.
138 MODERN PIGMENTS
"The color of viridian is a very deep bluish green of
great purity and transparency. It furnishes with aureo-
lin on the one hand and with ultramarine upon the other
an immense number of beautiful hues adapted to repre-
sent the colors of vegetation and water.
"It is quite unaffected by sunlight or sulphureted
hydrogen, and it has no eyil action of its own upon other
pigments. Moreover, it can be safely used with all the
painting media and upon all kinds of painting grounds."
It should be more extensively used by the carriage
trade, as it is just the sort of pigment that is needed for
a permanent glaze.
It is chiefly imitated by compounds of chrome yellows
and blues, but such are worthless; they possess neither
the brilliancy nor the permanency of viridian.
Its use is confined to the artist's palette and to the
GREEN PIGMENTS (Continued)
History and Production
THERE are to be found in various parts of the world, in
the New as well as in the Old, certain earths having a
variety of greenish tones. These earths vary greatly in
their composition, as one might well suppose, and in
consequence of this are diversified in their respective
Terre verte was made use of in the earliest attempts
at decoration, and is found upon ancient Roman
wall paintings. The prepared pigment itself has
been discovered in pots in the ruins of the city of
None of the various shades of this pigment are at all
vivid, and all partake of the tertiary order.
It is prepared for use in much the same manner as was
indicated for ocher and the other earth pigments which
already have been under notice by washing or levi-
gating to free it from its heavier impurities, and, after-
wards, separating into various grades, then drying,
The following analysis, made by A. H. Church, is that
of a sample from Monte Baldo in Italy. It shows that
terre verte is allied to the hornblendes, and that it is a
silicious-ferric product :
140 MODERN PIGMENTS
Analysis of Terre Verte
Water given off at 100 C. ...... 4.1
Water given off at red heat 4.2
Ferric oxide (Fe 2 O 3 ) 20.3
Ferrous oxide (Fe 2 0) 2.6
Potash . . . ; 6.4
From the composition shown by the analysis, a person
can at once infer that terre verte is little subject to change,
as all its constituents are themselves the product of any
and all possible change, and incapable of any further
Terre verte is only semi-opaque in character, and there-
fore covers indifferently well when mixed with linseed
oil or varnish. Its use in oil is limited to the producing
of certain neutral-toned greenish hues with a white base.
It possesses the quality of absolute permanency, and pro-
longs the life of white lead associated with it in the making
of tints. It does this because of its power of absorbing
large quantities of linseed oil, and acts in many respects
as do all the silicate earths.
It is chiefly used in water or distemper. In distemper
it covers well, and its neutral tones and that of its tints
are much better fitted for mural painting than it is in oil.
Some fine samples of it have been found in various
parts of New England, and many manufacturers grind it
under their proprietary names. Manufacturers of mixed
paints can also use it to good advantage for certain tints
on acbount of its imparting good wearing qualities and
because of its relative cheapness.
GREEN PIGMENTS 141
Chemistry and Preparation
Verdigris is the basic preparation of copper. It is a
permanent bluish green, and is made in large quantities
in Southern France, where the city of Grenoble is head-
quarters for its distribution.
It is produced from copper sheets or plates upon which
the grape pomace, obtained from the wine-presses so
abundant in that section, has been spread. By fermen-
tation, the acetic acid is combined with the copper, and
forms upon the surface a green rust which is verdigris
or the subacetate of copper. It can be manufactured
in various ways, but as the use of that pigment is becom-
ing more restricted every year, and as the description of
the processes would require more space than the little
usage that is made of it warrants, the above, which is the
principal method of obtaining it, will suffice, with this
additional note, that the raw product thus obtained is
afterwards manipulated to free it from impurities. It is
then crystalline, and in that shape it appears upon the
markets of the world.
Verdigris is a perfectly transparent pigment, and its