FAQ's on Pigments
What
are pigments? |
In biology, pigments are those substances which can
give color to the tissues or cells of animals or plants. The most
commonly available natural groups of pigments in the plant and animals
groups, are called Carotenoid.
What
are hinges? |
With pressure sensitive tapes, prints cannot be glued
or taped directly to a backing. For this purpose, hinges are used.
Hinges are made of special archival tape, linen, or fine Japanese paper.
All these methods use non-acidic, reversible adhesives, non-sticking.
How
does particle size affect a pigment's dispersibility? |
The sizes and shapes of particles of pigments have
great impact on the colors of these pigments. But, these pigments are
available in clusters form instead of individual form. The cluster
pigments also effect the tinting strength and grind of these pigments.
Many different mechanisms are there, which hold the pigments together
as a clusters. The most common mechanism is the soluble materials, and
these materials cement pigment particles together in the drying process.
When the sizes of the pigments particles start to decrease, theirs
surface area also decreases and consequently, the electrical
charge in these pigments increases. This increased charge in the pigment
particles make them more dispersed.
What
are the lightfast properties of the pigments? |
The resistance characteristic of these pigment
against the fading after exposure to sunlight, is called as lightfast
property of the pigments.
What
are Pigment Sticks? |
The stick form oil paints are called as Pigment
Sticks. These sticks consist of linseed oil, natural beeswax, and
pigments. Generally, pigment sticks are highly fluid and very smooth.
Sometimes, these sticks are also referred as Oil Sticks. These are used
in drying the pigments.
What
is the meaning of Luminescence? |
Luminescence is a kind of property which is found in
some materials. Through this property, these materials can trap the
energy, act on it and then emit this energy as light. The emitting
process my occur immediately or after long period of time in excess of
thermal radiation.
What
is the meaning of Fluorescence? |
When a substance is exposed to exciting radiation and
light starts to emit from the substance, then this process is called as
Fluorescence.
What
is the meaning of Phosphorescence? |
After the cessation of excitation, the afterglow that
can be detected by the human eyes, is known as Phosphorescence.
What
is the meaning of Brightness? |
In photometric term, the brightness can be expressed
as a "luminance". Brightness is used to measure the emitted
luminous intensity/unit area of a light source in millic andella/ m2 or
foot-lamberts.
How
does TiO2 provide opacity? |
When all of the visible light that falls on a
surface, is scattered, then only opacity is appeared. Titanium dioxide
is considered as an efficient light scatterer. When there is enough
pigment of TiO2 in an object or a film, only a small amount of light
will be absorbed by the pigments or polymer and rest of the light will
be striked off. The striked off light will be scattered outward and the
system will appear as opaque and white.
What
is the relationship between Phosphorescence and Temperature? |
The light discharged by a phosphor, hugely depends
upon the temperature. When phosphors are kept at high temperature, then
for a short period of time, these phosphorus rapidly discharge light.
But, when fully charged phosphors are kept at low temperature, then
their light discharging rate gets slower. That is why, whenever it is
required to test a matter, whether it is phosphorescent or not, the
standard temperature is taken. The standard temperature is 23° C.
Which
chemical and physical factors affecting the light fastness of
pigments and dyes? |
These following factors affect the light fastness of pigments and
dyes:
- The concentration of dyes and pigments.
- Chemical as well as physical structure of these substrates.
- Distribution of wavelength of incident radiation.
- The atmospheric conditions like the humidity in the atmosphere
and percentage of contaminants.
- Distribution of wavelength of the incident rays.
- The rate of diffusion of the volatile substances in the polymer.
NOTE: The lightfastness of the pigments and dyes do not
depend upon the pigment or dye, but depends upon the whole system.
What
makes one grade of TiO2 different than another? |
There are different grades of Titanium dioxide which
are available. These different categories of Titanium Dioxide are due to
the difference in their particle size and their surface treatment.
What
are the prescribed directions while using dry pigments? |
For methods of using dry pigments (or other
non-colored powdered additives) which require only as much mixing as is
possible with a brush. These methods can be applied for solvent or
water-based paints. It will not achieve the level of ground pigments,
but can suffice. Making the crude version of a pigment dispersion.
Manual grinding with a glass muller on a glass surface is recommended
(see- Grinding) Make a paste with dry pigment, water and disperse water
for water based paints or dry pigment, stand oil and disperse oil for
oil base.
Will
the organic color pigments stain the clothes or sheets? |
The color organic pigments are not stains nor these
are dyes. So, if some stains arise in the clothes or sheets, then after
some time these can be washed-out completely from any synthetic
materials. These stains can be removed very easily.
What
is a mixed metal oxide (MMO)? |
MMO is a kind of inorganic pigment. These type of
pigments contain more than one types iron metals in their oxide crystal
structure.
What
is a CICP? |
CICP are also a kind of pigments. These are Complex
Inorganic Colored Pigments.
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