on. By far the greatest quantity of it that found its
RED PIGMENTS 111
way into England, and from thence was exported to
America, was shipped from Bengal. Hence its name of
Indian red, by which it is best known in both countries.
It is a very rich hematite iron ore. Its coloring matter is
peroxide of iron. It is an anomalous red of a -purple-russet
hue, and highly valued when of good quality for its lakey
tones in making tints by compounding with a white base.
It is a coarse powder in its native state; full of hard
and extremely brittle particles of dark appearance and
sometimes magnetic. It is greatly improved by grinding
and washing. Its chemical composition is such that it
has a tendency to deepen. It is most permanent; neither
light nor impure air, mixing it with other pigments, time
nor fire, seem to cause it to change in any way.
Being very opaque, it covers remarkably well. The
tones of Indian reds vary greatly in their hues; that
which is rosy being considered the best, as affording the
As long as Indian reds were imported and consisted of
iron ores, and until such recent times as the eighties, there
was and could be no recognized standard of purity for it.
Containing great strength of coloring matter, it was the
usual thing to adulterate it with from 50 to 75 per cent of
makeweight foreign matter, and still it remained strong
enough to disarm the suspicions of the painters of that
period. Now, however, it is different. No Indian red
can be recognized as pure that does not show upon analy-
sis at least 95 per cent of peroxide of iron, and frequently
some are found to analyze 97 and 98 per cent pure. The
reason for this great purity is that to-day most of it is
made artificially, as pigments having iron as a coloring
agent are nearly all so made. It is thus possible to main-
tain a specific standard of purity in the processes of their
112 MODERN PIGMENTS
It is made in a similar manner to that related of the
manufacture of crocus used in the production of Venetian
red, with this difference, that instead of sulphate of iron
being the source of supply, iron pyrites replaces it.
The processes vary to some extent from that also ;
these are too complicated for description here, but may
be inferred. The sulphuric acid is driven from the pyrites,
and the residue forms the base of the Indian red.
Properties and Uses
A peculiarity belonging to all iron pigments, and also
common to Venetian red, is that the lighter the tone, the
stronger it will prove in coloring matter; thus the darkest
shades of them are the weakest in this respect. Hence
the rosiest of the Indian reds are the strongest.
Indian reds are selected and graded according to their
shade, and it is usual for color grinders to put them up in
three different shades the pale, or rose toned ; the medium
or the one between that and the dark which makes the
violet shades. The pale produces the rosy tints, and the
dark the lilac-toned ones. Indian reds are chiefly useful
for the making of a wide range of beautiful tints associated
with a white base. It is also used as a self color, but in a
very limited way.
It is employed by all classes of painters, decorators,
and artists for painting in oil, in japan, or in distemper,
and with universal satisfaction.
Tuscan red is a compound color; properly it is an
enriched Indian red. All that has been said of Indian red,
applies to it in a great degree, as that pigment is the
RED PIGMENTS 113
base. The enrichment is due to the use of a lake to dye
the Indian-red base and give it the beautifully subdued
As usually the Indian red is entirely too strong, its
strength is reduced by combining it with barytes, whiting,
or gypsum. The combining is done in a tank by the
addition of water with trituration. While still in a
diluted state, the lakes are added to the mixture. The
color is allowed to deposit, when the supernatant water is
withdrawn, the pulp color pressed out, dried and pul-
verized, packaged, and sold as Tuscan red.
Properties and Uses
It stands to reason that the better the lake used in
dyeing the Tuscan red, the better that will be in quality.
If the red has been colored up with the cheaper and
inferior aniline dyes, as in making the qualities of Tuscan,
it will fade away upon little provocation, and prove as
fleeting as rose pink and as prompt in disappearance.
Again, in the best grades of Tuscan reds the enriching
lake is practically permanent, or the manufacturers could
never guarantee them to stand 350 F. of heat before
any sign of changes taking place in any way. Tuscan reds
made thus are therefore very permanent, and are ex-
tensively used for the painting of passenger cars, one
of the most rigorous tests for any color; they are also used
with good results in the painting of steam pipes, radiators,
etc., another very hard test of the permanency of a color;
probably Tuscan red is more extensively used for such
painting than any other color. The quality test is the
all-important one for this pigment. The test for mere
strength of the amount of coloring matter contained
amounts to nothing, Tuscan reds being never used for
the making of tints. In this regard they are very inferior
114 MODERN PIGMENTS
to the Indian reds. They are used exclusively for solid
self-painting, and for this purpose are very much better
adapted than are the Indian reds, because they possess
far richer tones.
It is really difficult to test Tuscan reds. The staying
quality of tone is what counts with them, and that is not
easily determined on the spot time only can do that.
Some of the very poorest ones will show up bright and rich
when first taken out of a can. This is where confidence
in the name of the manufacturers will have to decide
which of two samples one shall buy. If they have an
established reputation made for their Tuscan red, let that
guide. When so found, better be slow in changing to
another that is unknown.
It is used by many manufacturers of machinery and
implements, and when it is properly striped with a light
orange it presents a fine effect. The machinery looks
rich but not gaudy, and it is a relief from the overdone
scarlet that it is customary to use for such painting.
RED OXIDE OF IRON
Properties and Uses
Within the past twenty-five years, the red oxide of iron
has been so listed by many color grinders. It is a power-
ful red and to be had in many shades. The scarlet shade
is the most preferred. These scarlet oxides are the
brightest and strongest known. They should be pure,
and this the scale test will reveal at once. When used
in oil, it should be thinned to the last degree, as it is so
strong that the color will not show at best advantage
unless it is so thinned.
It is chiefly valuable for the making of tints with white
bases where the least quantity of color is wanted to pro-
RED PIGMENTS 115
duce the desired effect. It is so very strong that one
pound of it will turn a ton of white lead to a decided
flesh tint. In other respects, it is of the same character
of red as the Venetian red, and it is questionable if it will
ever be able to take the place of that red even for the
making of tints, because the base (gypsum) in a good
Venetian red acts as a preservative to the white lead, and
in a small measure helps to retard chalking. This is
also partly due to the greater quantity of linseed oil which
a tint so prepared will contain.
Scarlet oxide of iron, notwithstanding that it is abso-
lutely pure, has never become popular among the painters.
It is now nearly twenty-five years since it was first offered
for sale in a regular way, but its growth into favor is so
slow that some grinders who listed it a few years ago
have abandoned it. At best it is a curiosity. Should
it ever grow into favor, it would soon be placed on sale
again, as it is as easily procurable as the crocus of the
Venetian red. The trouble is that it does not fill a
" long-felt want," and that it is only a stronger edition of
Venetian red, and that is of questionable value.
RED PIGMENTS (Continued)
History and Chemistry
THIS pigment was known to the ancients, and is of great
antiquity. It was known and used in the enameling of
pottery, brick, and terra-cotta by the Greeks and Romans,
and was used also by them in their decorative paintings.
It was formerly known under the name of minium, and is
still known under that name in many parts of the world.
It is the product of the oxidation of massicot, but it is
also obtained by the calcination and oxidation of white
lead. It is a double oxide of lead, massicot or litharge
being the monoxide of it. Its chemical formula is Pb 4 O 5 .
Properties and Uses
Red lead has the property of saponifying linseed oil to
the extent of about one third of the quantity necessary to
thin it for application with the brush. It is a very good
and strong drier of linseed oil, and for that reason, joined
to that of the saponification of it, it cannot be ground to a
paste form with linseed oil as most other pigments can
be, as it will solidify into a hard mass in a short time.
Owing to this peculiarity, which is a common property of
all the other oxides of lead, it is usual to buy it in a dry,
Red lead is a most excellent paint for use over iron as a
primer next to the bare metal. It is also a most excellent
RED PIGMENTS 117
primer for other metals, and it is becoming more important
every year now that so much structural iron and steel are
being used in the construction of buildings in all our
large cities. Engineers and architects are unanimous in
recommending it as a first or priming coat over iron, and
many specify it to be applied at the rolling mills. It is
the best primer that can be used for such a purpose.
Formerly it was extensively used in wagon painting for
the running gears, and some factories still use it in that
way. It seems to adhere with such tenacity on the wheels
that it is not easily scratched or marred. The felloes of
wheels painted with other materials soon show.
Like all lead pigments it is easily affected by sulphur-
eted-hydrogen gases, and it will turn black when exposed
to them. When exposed to the direct action of the sun's
rays it has a tendency to bleach. This is no doubt due
to the loss of some of its oxygen and to a return towards
a monoxide state, the normal condition of the lead oxides.
As to its wearing qualities, there is nothing in the line
of pigments that equals it. It becomes nearly as hard as
a coat of metallic lead itself some say harder. As has
been said, a wagon's running gear painted with it will
stand knocks, friction, and anything in reason without the
paint coming off, while any other red would come off to the
At the several navy yards of the United States, but
especially at Norfolk, Va., the authorities have come to the
conclusion that there is nothing to equal it for the priming
of iron, and they specify its use for that purpose in ship
construction. Again, when at the end of a cruise ships
come in for a general overhauling in the dry docks, and
after the old paint has been burned off, they are invariably
treated to a coat of red lead as a foundation for whatever
may be wanted to go on top of that.
118 MODERN PIGMENTS
On account of its heavy weight, it is never used in dis-
temper; and from its tendency to blacken under the action
of sulphurous fumes and to lighten under strong sunlight,
it is never used for that kind of work.
Its chief and best use is when associated with linseed
oil for the purposes already indicated.
Many of the white lead corroders also make red lead.
This they put up in wooden kegs of same weights as those
of white lead, viz., 12J's, 25's, 50's, 100's, 200's, and 250's
being the usual quantities. It is usually pure when the
label says "Strictly Pure/' and is accompanied by the
name of the corroding firm. There is some difference in
the qualities of it, some being more crystalline than others,
and therefore richer in tone. It therefore requires some
little knowledge of brands to be able to buy the best
without seeing them first. For the priming of structural
iron, this does not make any material difference; but if
the lead is to be the finishing coat, as in wagon-gear paint-
ing, then that is another story.
The above ends the list of useful red pigments
employed in general painting; the remainder are mainly
compound pigments and the lakes, which are seldom
handled in general painting excepting in tinting or color-
ing walls and for decorative purposes. The car and
carriage painters, however, use some of these extensively.
The japanning works also use them, and some are used
for enameling pottery and colored brick.
General Remarks Concerning Them
Under the generic name of lakes, a class of pigments
is placed upon the market which differs in one respect
from all the others. As a rule they are transparent, and
RED PIGMENTS 119
are never used alone as a covering coat in oil painting.
When used in oil or varnish, it is over some other coat
of color which sometimes is similar in tone to that of
their own, but which has made a solid covering, and they
are used in that case for enriching it. Or if placed over
a color which is dissimilar in tone to their own one
that will show through their own coating, which permits
certain effects to be thus produced which would not have
been possible otherwise. This is called glazing, in the
parlance of the craft. That is their chief use in oil or
varnish. Some also make beautiful tints with white lead
or zinc white bases, especially the latter, and that with
any of the vehicles.
Lakes are extensively used by the wall-paper manu-
facturers, and in distemper by all classes of decorators
and artists. The car and carriage trades also use them
largely, and artists would hardly know how to get along
Lakes are invariably made by the use of a dyeing
agent upon a base that it is calculated will best hold it.
For this purpose, many substances and combinations of
them are used. Alum is commonly the principal one,
but gypsum, whiting, and barytes are also employed for
Among the reds are to be found some of the most valu-
able and permanent of the lakes. This permanency was
originally due to the use made of coloring matter
extracted from the madder plant. This is now obsolete,
as the same coloring substance which was at one
time extracted from the madder root is now much
more economically extracted from coal tar as alizarin
120 MODERN PIGMENTS
ALIZARIN AND PURPURIN
Extraction and Preparation
Church says: "Both of these coloring substances are
now made from anthracene. This compound occurs in
coal tar in a crystalline fluorescent hydrocarbon C 14 H 10 .
By a series of processes this substance gives rise to
alizarin and purpurin, which are in all respects identical
with those coloring matters derived from the madder
plant itself. The artificial alizarin of commerce contains
several other coloring matters, two of which are better
known than the others: these are anthrapurp^irin
(C 14 H 5 O 8 ) and purpuroxanthin (C 14 H g O 4 ). Purpurox-
anthin is also present in the natural pigments derived
from madder root, but it exists in smaller proportions.
Of all these compounds alizarin is the most important
and best known, and yields lakes having various hues of
crimson, rose, purple, violet, and maroon according to its
purity, its concentration, and the nature of its base
(alumina, iron oxide, or lime with alumina) with which
it is associated. The purpurin and anthrapurpurin
resemble each other closely, and give pigments
which are generally characterized by more orange and
red hues than are those obtained by alizarin. The
rose and pink madders and madder carmines of com-
merce are generally so manufactured as to include for
their coloring constituents much alizarin and very
The process of extracting alizarin and purpurin from
madder root or from anthracene is far too lengthy and
complex for this treatise. It suffices to know that it is
now possible to obtain, at a comparatively low cost,
excellent pigments which twenty-five years ago would
have been very expensive.
RED PIGMENTS 121
Manufacture of Lakes
The preparation and manufacture of lakes from
eosine, anilines, alizarin or purpurin, present no difficul-
ties. Of course, one must be provided with the proper
Madder lakes can be readily prepared from alizarin
and purpurin, by dissolving those substances in the
smallest necessary quantity of alkali, such as ammonia
or sodium carbonate, or some pure, freshly precipitated
and thoroughly washed aluminum hydrate. While the
above directions are simple, there is more to that simple
process than appears upon the surface. There are many
little tricks of the trade that are secrets, and which are
used in the precipitation of lakes, which enable one color-
maker to produce from the very same substances a lake
that looks brighter or which is more permanent than
that made by another manufacturer.
Fixing the coloring matter is an important item in the
manufacture of lakes. As an illustration of how trifles
affect coloring matter and its durability, an incident,
the truth of which can be vouched for, is given as follows :
The world-wide known and justly celebrated govern-
ment institution in France the "Gobelins" where
the famous historical tapestries are manufactured, pre-
pares all the dyes used in the coloring of the wool. In
earlier days there were no underground sewers in that part
of the city of Paris, and surface streams were depended
upon for the carrying away of all sorts of liquids. It
happened that a small brook formed the middle of the
street in front of the factory, and that the water used for
the preparation of the dyes was taken from it. The
water was very impure and fetid, as it was contaminated
with animal matter from an abattoir (slaughter house)
122 MODERN PIGMENTS
above it. In the course of the city's improvement, the
stream was diverted and made to flow into underground
sewers, so that the Gobelin factory was forced to use city
water in compounding its dye stuffs, but some of the most
admired shades could not be reproduced. It puzzled the
heads of the institution for many years, searching for the
cause of their inability to reproduce the beautiful color-
ings made in former years. At last they hit upon the
cause, and, as nearly as possible, they artificially con-
taminated the pure water furnished by the city to resemble
that which they had once used, and thereupon they were
able to reproduce the shades as of old. These were due
to the impurities contained in the water. This illustrates
why it is that some manufacturers are able to and do put
out brighter and better goods than another can. This is
due in many instances to the water, or rather to the
composition of the water used.
Properties and Uses
Rose pink is a very cheap lake of purplish-red tone, and
about the poorest one in the whole range of red lakes.
Its coloring matter is evanescent. It should never be
employed for lasting work.
It is used for coloring fillers in furniture factories, also
by some for staining cheap furniture and chairs. It
looks rich, and usually remains so long enough to enable
the furniture manufacturers to dispose of the goods before
The best of it is usually made from Brazil wood ; some
of the cheapest of the cheap aniline dyes seem to have
gone in the makeup of many samples of it. As there is
danger to those who use this pigment they may be
RED PIGMENTS 123
using some of the aniline-made ones unless one is sure
of the brand being a good one, it will be best to let it
alone and take no chances. Much better lakes can be
had which produce the same effects, but they cost more.
Properties and Uses
This lake is just one notch better than rose pink. It
belongs to the same order and tone of red, but, as usually
made, is just a trifle lighter toned and more rosy. It, too,
is made from Brazil wood when it is not made from
something else (aniline).
Like rose pink it fades away quickly upon exposure
to strong light, and but for the fact that one is charged
a little more money for it than for the other, it would be
hard to tell which is the poorer of the two. In reality
it is simply a lighter shade of rose pink, of a more rosy
tone, or not quite so purplish.
The same caution given under the heading of rose
pink not to make an indiscriminate use of it will
apply with full force to rose lake. This is also
employed for the same purposes.
Properties and Uses
Under this name will be found all the red lakes found in
commerce that are of any good at all. Accordingly, all will
be listed under the same heading, all such at least that
are made by the agency of alizarin and purpurin. These
lakes have quite a wide range of tone, and cover the whole
field of maroons, violets, and the pinks, including the
124 MODERN PIGMENTS
It is useless to examine them separately, as all have the
same general characteristics, the difference being simply
one of tone. Each of them will, of course, make a line
of tints appertaining to its coloring.
All color manufacturers usually put out several lakes
under fancy and proprietary or copyrighted names.
Coach color catalogues and price lists are frequently a
puzzle to the uninitiated because of some dozens of red
lakes of whose existence but few may be aware. Many
are never mentioned by the other competing firms, who
have a puzzling list of their own. Dry color lists are also
swelled up and loaded down with terms to the confusion
of the average reader. Each manufacturer adopts a
name of his own for something that is identically the
same as that chosen by other competitors, each of whom
calls it by a different name. This practice is highly confu-
sing to persons who are not familiar with the trade custom
nor with the exact character of the goods themselves.
Therefore, if a person has been buying a red lake under the
glowing name of "Morning Star," and he finds one that
matches it but offered for sale under the name of " Setting
Sun," he need not worry if he is forced to use the latter.
In all likelihood they are identical, and he will not be
disappointed in their use. The main point is to insist
upon getting an alizarin or purpurin red, and the dealer's
guarantee that such a lake is thus made is the main thing.
Dealers who handle lakes should be able to answer such
questions; and, if they were questioned a few -times, would
be forced to post themselves if they do not already
know and the y should know what sort of material
they handle and offer for sale.
The madder reds and madder lakes are, all of them,
what may be called permanent under proper conditions,
and can be called so by contrast and in comparison with
RED PIGMENTS 125
those made from cochineal, Brazil wood, etc. They are
very satisfactory in use. The range of color, covering
as it does every shade of red, purple, and maroon, is
sufficiently varied for the wants of any one. As they
enter into the composition of the better class of vermilion
reds, these might also be classed with them; thus the field
of reds would include the scarlet tones. However, those
reds are solid opaque covering goods, in nowise trans-
parent, and they cannot be included with the lakes.
There are a number of reds made in a manner similar
to the lakes, but upon an opaque base. These are used
for solid painting on that account, and for that reason
these reds cannot be classed with lakes.
The crimson solid-covering reds are chiefly used by
the carriage trade, and are known under various names,
unfortunately all proprietary, thereby causing more con-
fusion. Of this description are the many road-cart reds,
so called. The cheaper kinds of those reds are made
from cheap aniline dyes, and are therefore fugitive; the
better are from alizarin and purpurin, and they conse-
quently are durable.
The scarlet and the carmine-toned lakes are intended
to imitate the true carmine obtained from cochineal.
This they cannot do in reality, for if placed side by side,
the cochineal carmine is the richer by far for a few days.
Change that to a few weeks, and the alizarin carmine will
become the brighter and richer of the two. An expos-
ure of six weeks will do that. v
These lakes (the whole range of them) are useful in