What’s Pigment and Its Physical Basis?

A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.

For industrial applications, as well as in the arts, permanence and stability are desirable properties. Pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, while some eventually blacken.

You don’t just find pigments for paint, but also for coloring ink, plastic, fabric, cosmetics, food, and other materials. Most pigments used in manufacturing and the visual arts are dry colorants, usually ground into a fine powder. This powder is added to a binder (or vehicle), a relatively neutral or colorless material that suspends the pigment and gives the paint its adhesion.

Pigments appear the colors they are because they selectively reflect and absorb certain wavelengths of visible light. White light is a roughly equal mixture of the entire spectrum of visible light with a wavelength in a range from about 375 or 400 nanometers to about 760 or 780 nm. When this light encounters a pigment, parts of the spectrum are absorbed by the molecules or ions of the pigment. In organic pigments such as diazo or phthalocyanine compounds the light is absorbed by the conjugated systems of double bonds in the molecule.

The appearance of pigment for coating is intimately connected to the color of the source light. Sunlight has a high color temperature, and a fairly uniform spectrum, and is considered a standard for white light. Artificial light sources tend to have great peaks in some parts of their spectrum, and deep valleys in others. Viewed under these conditions, pigments will appear different colors.

Naturally occurring pigments such as ochres and iron oxides have been used as colorants since prehistoric times. Archaeologists have uncovered evidence that early humans used paint for aesthetic purposes such as body decoration.

Before the development of synthetic pigments, and the refinement of techniques for extracting mineral pigments, batches of color were often inconsistent. With the development of a modern color industry, manufacturers and professionals have cooperated to create international standards for identifying, producing, measuring, and testing colors.

Selection of a pigment for a particular application is determined by cost, and by the physical properties and attributes of the pigment itself. For example, a pigment that is used to color glass must have very high heat stability in order to survive the manufacturing process; but, suspended in the glass vehicle, its resistance to alkali or acidic materials is not an issue. In artistic paint, heat stability is less important, while lightfastness and toxicity are greater concerns.

Milk paint Pigments – The Natural Way To Go

Following the industrial revolution decorative color pigments from atypical sources, like botanical substances, animal waste, mollusks and insects, where yielded and traded over long distance.

Pigments made from the female form of the "Cochineal", an insect inhabitant to Central & South America, are still employed nowadays in food, dye, plastics, body paint and fabric. These pigments were employed by Peruvians since prior to the eighth century and they were too employed by the Catholic Church for its cardinal vestments. Pigments based on clays and minerals often bore the name of the region or city where they were excavated. Burnt Sienna and Raw Sienna came from Sienna Italy; while Burnt Umber and Raw Umber are from Umbria.

Pigments powders can be blended with and employed to concrete, color stucco, resins, plaster, epoxies and wood putties, employed in milk paint as a binder or blended with other pigments for paint to transform the color or put in intense color.

Master painters of the regeneration era made their own materials and tools, including paints. Master painters took on learners to perform much of the job of preparing substances, making tools, and blending pigments. In exchange of their efforts, the learners learned the methods of painting from the masters.

Several premature Renaissance artists employed gold leaf as a backdrop to their gesso treated paint boards; a layer of clay followed and eventually the gold leaf was executed, employed only to improve a mystic halo effect over a Madonna, or a fire. Keep in mind that this procedure wasn’t just time taking, gold was very costly and hence employed very rare.

Today we’ve all of the same pigments for coatings dating back to the prehistoric Egypt and more but diverse synthetics and chemicals have been incorporated to the listing. The fashion, though, is towards the more natural milk paint kind items.

We now add in most of these methods in the same manner that they were employed in the earlier days but we’ve incorporated chemicals that have an effect on the greening of our earth in an unconstructive manner. Fortunately, things are changing and lesser chemicals are being employed nowadays and the ones that we do utilize are cautiously checked by government bodies.

Nowadays we notice a radical transformation in our surrounding and the way we view it. Natural pigments are employed more frequently as we came to know how to recognize the worth of safeguarding our natural supplies.

The utilization of milk paint, that employs organic pigments, looks to be the best way to go.

Various Uses of Pigments

Pigments are employed in a number of applications from the design on that new t-shirt to the shade of your shoes. But that isn’t all; pigments are also employed to color cosmetics, plastics, medicines, building materials like vinyl and brick cladding, the books and magazines we read, paints of all sorts and even the foods we consume.

Obviously, food coloring varies significantly from the pigments for paint. And while organic dyes may be employed for coloring garments made of cotton or wool, they aren’t as bright as pigments. Food coloring must be apposite for human use, while the color in garment has to be from a supply that won’t cause skin annoyance. Food coloring & organic dyes comes from plants like fruit, herbs, vegetables and non-toxic leaves.

So you must be wondering where do pigment come from? Numerous pigments are mined from minerals like zinc, titanium or magnesium. These materials are ground into a fine particle and a fluid called an agglutinant is incorporated. This fluid can be water or oil based relying on what it’s going to be employed for. Pigment particle is insoluble, whereas food colorings and natural dyes are soluble.

Pigments that are employed to color such things as airplanes or model cars to make them appear more practical vary from those pigments that are incorporated to cosmetics or house paints. Pigments to be utilized in visual pursuit such as modeling or painting can be purchased from any art-supply store.

Industrial pigments for coatings are incorporated to such things as plastics throughout the practice of forming the items, rather than later as in an item that’s painted. Collecting pigments was once a tedious job but it is now as easier as you could imagine. Synthetic pigments that are safer and cheaper are now widely employed in a number of commercial applications.

The Use of Pigments in Various Industries

Pigments are colored elements employed for coloring in many critical industries. Furthermore, pigments are known to provide a vivacious choice of colors to the substrate they’re used on. They’re unsolvable in water and don’t bring about any chemical or physical change on the substrate that they’re used on. There have been several researches being performed because of its increasing significance.

Orches and iron oxides are the organically occurring pigments for paint that have been employed as colorants since the prehistoric age. Excavations at different archeological sites globally have produced proof that pigments were employed in painting caves. Coloring body for artistic reasons & dying the antique clothes. The source of these happens to be animal wastes, plants and botanical materials. Therefore, these were largely organic pigments. Following the industrial insurrection, pigments started to be produced synthetically employing chemicals.

There’re resourceful coloring agents or colorants avail with flexible characteristics which provide reliability to its aptness in various mediums. The main features of pigments are the following:

• Great light-fastness

• High solvent resistivity

• High baking solidity

• Great weather resistant

• High heat stability

• High tinting potency

• Easily dispersible

• Great over-spray fastness

• Uniqueness & consistency of shades

These above-mentioned aspects have made the pigments a much required commodity among various industries.

Application of pigments:

These days you can find the application & role of pigments span across several industries. Most of the industries today use pigments eventually in their customarily production activities. These are employed both as raw materials and finishing materials as well. Some of the main applications of pigments are:

• Papers

• Paints

• Biomedicine

• Oil and resin based emulsions

• Nylon

• Cosmetics

• Plastics

• Distempers

• Printing inks

• Polyesters

• Lacquers

• Cement glass pains

Due to the various uses and considerable application of pigments, its significance across industries can’t be ignored. The creation of pigments for coatings is bound to improve in the coming years. The scientists are now attempting to synthesize pigments that aren’t just high on durability but also eco-friendly at the same time as well. Eco-friendly pigments certainly would have a positive greenhouse effect.

For special pigments and aqueous pigment dispersions contact WC Manufacturing. Apart from specialty and traditional pigment dispersions, they also supply industrial and food grade dyes. Their products are used in a range of markets including the paper coating industry, paintballs, bingo and other specialty marker inks. Get in touch with us now for a better deal.