The Science of Pigment – Mocomi.com

Science Of
Pigment

Chemistry for Kids

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INTRO

SCIENCE OF
PIGMENT

All paint is made from an essential ingredient known as pigment. These tiny particles
are ground coloured material were first extracted from earth or clay. Even though we
continue to use age old processes to prepare
pigments and convert them into paint,
modern pigments are synthesized in laboratories.

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INTRO

SCIENCE OF
PIGMENT

The following properties are taken into consideration when talking about the quality of both
synthetic and natural pigments:

Lightfastness: the rate at which a pigment
fades when exposed to light.
Heat stability: how pigments react when exposed to heat.
Toxicity: the degree to which it can damage a
living or non-living thing.
Tinting strenght: how much pigment is required to produce a particular shade.
Opacity or transparency: whether one can
easily see the under layers of paint
once the top layer is dry.


BLUE

SCIENCE OF
PIGMENT

The source of blue pigment used to make

ultramarine

is the semi-precious
stone- lapis lazuli. Natural ultramarine is
the most difficult to produce because the
hard lapis lazuli must be ground into a fine
powder in order to make paint. The earliest
noted source of the colour were in Afghanistan.

Blue

was used very sparingly in art because of how difficult this colour was to
produce. Artists would go as far as to only
paint the top layer of blue with ultramarine
to cut down costs of painting.


BLUE

SCIENCE OF
PIGMENT

Azurite is a soft, blue mineral of copper

that has many uses including the production
of blue pigment. The process to produce the
colour azure is similar to making its more
expensive cousin.
However, since it is a mineral of copper, the
pigments turn slightly green when added to
oil and green-gray when added to egg yolk
(also used as a base in natural paints).


BLUE

SCIENCE OF
PIGMENT

Another shade of blue that has an extensive
history is Indigo. The colour Indigo is
named after India, the earliest known production center of this pigment. The relatively cheaper means of production than ultramarine made the colour an important
trade commodity.
It was exported west as far as Greece and
Rome in the 7th century BC as a luxury
item. Indigo is produced by fermenting the
leaves of the Indigofera tinctoria plant and
mixing it with dye to form a blue-coloured
powder.


BLUE

SCIENCE OF
PIGMENT

Cerulian blue

was discovered in 1805
by a man named Andreas Höpfner. It is
made from cobalt and is prized because of
its pure colour. It is particularly prized in
the art world because it is opaque, it does
not fade easily, and it does not emit any
hues of green (unlike other blue pigments).


RED

SCIENCE OF
PIGMENT

Vermilion is an opaque orange-red pig-

ment that occurs in the mineral cinnabar.
It is one of the oldest used colours in the
world as cinnabar is a common mineral
found around the world.
The mineral is ground into a fine powder
and heated with mercury and sulfur before
it is ready to be mixed with a paint-base.
However it is also used without these chemicals like in India where married women use
Sindoor, a red streak of vermilion in the
parting of their hair.


RED

SCIENCE OF
PIGMENT

Carmine,

also known as crimson lake
or cochineal red is a bright red colour derived from the aluminium salt of carminic
acid. This might sound complicated but this
acid is found naturally in the cochineal
insect.
The insects are dried and boiled in water to
release the pigment. The water is them
treated with a chemical to make this liquid
into a powdered pigment.


RED

SCIENCE OF
PIGMENT

Madder lake sounds like the name of

a body of water in a fairytale but in fact
is the name of a pigment that has been used
for centuries. This natural pigment is extracted from the roots of plants of the
'madder' family.
The outer brown layer of the root gives a
common variety of the dye while the inner
yellow layer turns bright red when fermented.


GREEN

SCIENCE OF
PIGMENT

Malachite is used in the production of

green pigment much in the same way as Ultramarine. This copper carbonate mineral
occurs naturally in the Ural mountains of
Russia, many parts of Africa, France, Italy
and the United states.

Paris green is an inorganic compound

of copper. This poisonous substance is
named Paris green because it was used to
kill the rats in Parisian sewers. The compound can be ground into a fine powder to
produce a lighter, vivid green or left
a little coarser for a darker shade.
It is used even today in paint
production despite its high
toxicity.

GREEN

A

SCIENCE OF
PIGMENT

highly

expensive green pigment is
Cobalt green, made from the element
from which it gets its name. The green extracted from cobalt fades very easily when
exposed to light. The combination of high
cost and because it fades easily is the cause
for its disuse. However scientists found that
cobalt has certain magnetic properties that
has increased the efficiency of computer
storage devices.


YELLOW

SCIENCE OF
PIGMENT

The colour India Yellow used to be
produced by collecting cow urine of cattle
that had only been fed mango leaves. The
urine was collected in pots and heated over
a fire. The concentrate was filtered and the
remaining sediment was made into balls,
then dried and then made into yellow paint
in Europe. It was a preferred shade of yellow
because of its florescent hue.

Naples yellow,

also known as antimony yellow, is one of the oldest synthetic
pigments around. The old masters of Europe
used this pigment extensively but is
not used anymore because
it is very toxic.


YELLOW

SCIENCE OF
PIGMENT

The colour gets its name from the natural
deposits of lead antimoniate which was extracted from Mt. Vesuvius just outside of
Naples.

Hansa yellow is a synthetic pigment

used in inks, and oil and acrylic paint. It
was first made in Germany just before WWI
and has replaced its predecessors such as
Cadmium yellow, Chrome yellow,
orpiment, and gamboge because
it is not toxic.
For more such fun chemistry articles and videos, visit:
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Image references:

Indian pigmants
source: www.wikipedia.org. This file is licensed under the creative commons attribution 2.0 generic.


The Science of Pigment – Mocomi.com

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The Science of Pigment – Mocomi.com