Paints and Pigments

Paint

mixture of solid coloring matter, suspended in a liquid medium which is used as a protective and/or decorative coating for suitable various surfaces such as walls or canvases.

Pigment

a solid, colored substance made of tiny particles that gives paint its color. It is suspended in the liquid medium of paint but does not dissolve in it.

Pigment: 20%

Solvent: 15%

Binder: 40%

Extender: 20%

Additive: 5%

Composition of Excellent quality paint

Enamel Paint

a type of paint made by adding zinc or lead to varnish, known for forming hard, glossy, and easy-to-clean coatings. It is waterproof, chemically resistant, and offers good color retention, but dries slowly and often requires a titanium coating before use.

Oil Paint

a type of paint that uses white lead as its base and is typically applied in three layers: primer, undercoat, and finish coat. It provides durable, glossy or matte finishes, is easy to apply and clean, and is affordable. However, it dries slowly and is not ideal for humid environments.

Emulsion Paint

a fast-drying paint that uses polystyrene or polyvinyl acetate as binders and contains driers like manganese and cobalt. It can be oil- or water-based, offers good color retention, durability, and alkali resistance, and is commonly used for its quick hardening properties.

Cement Paint

a durable, waterproof paint available in powder form and mixed with water before use. Made from white or colored cement with added pigments and additives, it requires two coats for effective coverage and takes about 24 hours to dry fully.

Bituminous Paint

a black-colored paint made from tar or dissolved asphalt, known for being waterproof, alkali-resistant, and effective in preventing rust on metal surfaces. However, it is not suitable for areas exposed to direct sunlight, as it deteriorates over time.

Plastic Paint

a quick-drying paint that uses water as a thinner and comes in a wide variety of colors. It provides excellent coverage and is commonly used for interior surfaces.

Anti-Corrosive Paint

a black-colored paint made from linseed oil, fine sand, and zinc chrome. It is chemically resistant and forms a protective barrier that prevents water and air from reaching metal surfaces, effectively reducing corrosion.

Cellulose Paint

a fast-drying paint made from amyl acetate, celluloid sheets, and photographic films. It provides a hard, smooth finish and is resistant to water, acids, and smoke. Though costly, it is valued for its high performance and quality.

Pigments

give paint its color; water-and-oil-insoluble natural synthetic products that impart color to materials such as paper and plastics.

Vehicle

combination of synthetic resins and oils that surrounds the pigment particles.

Film

forms the protective film through oxidation and polymerization of the unsaturated constituents of the drying oil.

Thinners

suspends pigments, dissolve film-forming materials and to thin concentrated paints for better handling.

Driers

accelerates the drying of the film through oxidation and polymerization

Anti-skinning Agents

prevents gelling and skinning of the finished product before application

Plasticizers

gives elasticity to film, thus minimizing or preventing cracking

Paint Failure

it is the loss of adhesion or effectiveness of a paint coating, causing it to no longer protect or serve its intended purpose.

Alligatoring

is a type of paint failure where the surface cracks in a pattern resembling alligator skin. It occurs when a rigid paint is applied over a flexible one or due to aging and weathering of oil-based paints.

Bubbling

is a paint defect where blisters or bubbles form due to moisture, heat, or uneven drying—often caused by painting on damp walls or under direct sunlight.

Chalking

is the formation of a powdery residue on the paint surface due to oxidation and breakdown of the paint film over time. Rapid chalking is known as erosion.

Flaking

- is the detachment of paint from a surface, often caused by poor adhesion due to dirt, grease, or moisture seeping behind the paint.

- also called peeling

Fading

the gradual loss of paint color, usually caused by prolonged exposure to direct sunlight or using the wrong type of paint for the surface or environment.

Pigments

play a role in protecting the film by reflecting the destructive ultraviolet light, to strengthen the film and to impart an aesthetic appeal.

Extender

is a natural substance added to paint to improve durability, reduce cost, and enhance resistance to corrosion and wear.

Resin-emulsion paint

widely used since the Second World War, apparently, latex or also termed as "rubber-base" paints introduced commercially only in 1948.

Dye

- is a colorant that dissolves directly in liquids and is absorbed by the material it colors.

- are primarily used in the textile and paper industries for coloring fabrics and paper.

organic, inorganic

Types of Pigments

Organic Pigments

- Naturally occurring or synthetically made pigments based on carbon chains and rings

- Chemically simple but highly stable

- Traditionally sourced from plants and animals

- Most modern types are synthetic, derived from coal tars and petrochemicals

- Common in inks, plastics, and paints due to their vibrant colors

Inorganic Pigments

- Also called synthetic pigments, made from ground minerals, metals, or metallic salts

- More opaque and less soluble than organic pigments

- Known for excellent lightfastness (resistance to fading) and lower cost

- Commonly used in paints, plastics, inks, and synthetic fibers

- Widely favored in industry despite some drawbacks (e.g., limited color range or environmental concerns)

White Pigments

Used to enhance properties and reduce costs in industrial applications

White Lead

one of the oldest artificial white pigments, with the formula 2PbCO₃·Pb(OH)₂. It offers high covering power and easy application, commonly used in varnish paints. However, it reacts with sulfur gases and becomes chalky over time.

Dutch Process

a traditional method for producing white lead, where cleaned and coiled lead sheets are placed in earthenware pots, then buried in horse manure for about two weeks. The heat and vapors cause the lead to corrode, forming white lead pigment.

Stack/Chamber Process

Dutch Process is also known as what?

Levi Carter

Invented the Carter Process

Carter Process

faster method for producing white lead. It involves tumbling small lead particles in a rotating drum while spraying acetic acid and passing hot carbon dioxide and air for 5 to 12 days. This "quick process" yields a finer, whiter, and more uniform pigment than the traditional Dutch method.

Basic Sulfate

is a white pigment made by subliming galena ores (lead sulfide) with some zinc sulfide. It forms basic lead sulfate with a bit of zinc oxide and is more resistant to sulfur than regular white lead.

Zinc Oxide

- zinc white

- is a bright, non-yellowing white pigment with high opacity and UV resistance. It resists atmospheric gases, prevents chalking, and hardens paint films.

American Process

is a method of producing zinc oxide by reducing zinc ore with coal in a furnace. The metallic zinc is vaporized, then oxidized upon contact with air to form ZnO. The product is collected, with coarse and fine particles separated and reused if needed.

Wetherill Process

American Process is also known as?

French Process

- indirect process

- a method of producing zinc oxide by melting zinc in a furnace, then vaporizing it. The zinc vapor reacts with oxygen in the air to form ZnO, which is then cooled, collected, and tested for quality.

Lithopone

a brilliant white pigment made from barium sulfate and zinc sulfide. Developed in the 1870s as a safer alternative to white lead, it is non-toxic, fine, and inexpensive. It is widely used in paints, inks, paper, and interior coatings like water-based paints.

titanium dioxide

- also called titania

- is a white inorganic compound known as "the perfect white" or "the whitest white" for its intense brightness and whitening power. It is non-toxic, non-reactive, and widely used to enhance the whiteness and brightness of products like paints, plastics, and coatings.

titanium dioxide

is the whitest and brightest pigment known, with strong reflective properties that can scatter and absorb UV rays. It is widely used in paints, plastics, and coatings, making up over 50% of global pigment use.

Barium Sulfate

- Is a stable, inert, and transparent pigment.

- Though occasionally used as a white pigment, it is more commonly used as a filler or extender in rubber, plastics, paper, and textiles.

- Developed in the late 18th century as a non-toxic alternative to lead white, its synthetic form is called Blanc fixe.

- Also known as barite

carbon black, graphite, lampblack

Types of black pigments

Black Pigments

They slow the drying of linseed oil, helping extend paint life. However, they should not be used directly on iron or steel, as they can cause corrosion.

nigrosine

Black dyes like ________ are also used, especially in black lacquer formulations.

ultramarine blue, prussian blue, cobalt blue

Types of blue pigments

Ultramarine Blue

A synthetic blue pigment made from sodium aluminum silicate and sulfur. Originally derived from lapis lazuli, it's now widely used in laundering to neutralize yellow tones in fabrics.

Prussian Blue

A deep reddish-blue pigment made from ferrous ferrocyanide. It's a synthetic pigment used in paints and to produce green pigments like lead chrome green.

Cobalt Blue

A stable blue pigment made by heating cobalt oxide with alumina (CoAl₂O₄). Lighter than Prussian blue, it's used in ceramics, glass (as smalt), jewelry, and paints.

red lead, ferric oxide, venetian red, indian red

Types of red pigments

Red Lead

Bright red‑orange primer pigment made by oxidizing lead; prized for its corrosion‑inhibition on iron and steel.

Venetian Oxide

Deep red iron‑oxide pigment produced from iron‑sulfate waste; used in paints, primers, and rubber mixes.

Venetian Red

Blend of ferric oxide and calcium sulfate made by heating ferrous sulfate with lime; very durable on wood but not ideal for iron due to sulfate ions.

Indian Red

Natural hematite ground to a fine powder (80-95 % Fe₂O₃); valued for its earthy, permanent red tone in coatings.

ocher, chrome yellow, zinc yellow

Types of Yellow Pigments

Ocher

A natural yellow pigment made of clay and 10-30% ferric hydroxide; weak in tinting strength and now largely replaced by synthetic yellow iron oxides.

Chrome Yellow

A bright, affordable yellow pigment with strong tinting power and good lightfastness; made by reacting lead salts with sodium dichromate.

Zinc Yellow

A yellow chromate pigment with low tinting strength but excellent corrosion resistance; used in primers for steel and aluminum.

lead chrome green, chromium oxide, guignet's green

Types of Green Pigments

Lead Chrome Green

A synthetic pigment ranging from grass to deep green, made from lead chromate and ferrocyanide compounds; limited in use due to lead toxicity.

Chromium Oxide

A dull green pigment with excellent chemical resistance and lightfastness, made by fusing chromates with sulfur; used in durable paint systems.

Guignet's Green

- Emerald green

- A bright, permanent green pigment made from hydrated chromic oxide by heating potassium dichromate and boric acid.

burnt sienna, burnt umber, burnt ocher, umber, Van Dyke brown

Types of Brown Pigments

Van Dyke brown

is a native earth of indefinite composition, containing oxide of iron and organic matter.

Toners

are insoluble organic dyes that may be used directly as pigments because of their durability and coloring power.

Para red

is formed by diazotizing p-nitro-aniline and coupling it with β-naphthol.

Toluidine toner

a better and more expensive red pigment, is made by diazotizing m-nitro-p-toluidine and coupling it with β-naphthol.

Ransa yellow G

- lemon yellow

- is manufactured by diazotizing m-nitro-p-toluidine and coupling it with acetoacetanilide.

Ransa yellow 10 G

- primorse yellow

- is made by coupling ortho-chloroacetanilide with

diazotized 4-chloro-2-nitroaniline.

Lakes

result from the precipitation of organic colors usually of synthetic origin upon some inorganic base.

Lake Colors

are very popular synthetic food color and their coloring is achieved by dispersion of colors that have different concentrations.

Metallic Powder

- are fine metal or alloy particles used in coatings for both decorative and protective purposes.

- bronze and aluminum powder

bronze and aluminum powders

often used in lacquers for their shine

Aluminum flakes

serves as light-reflective pigments and anti-corrosive primers for metal surfaces.

Pigment Extenders

- are white, low-opacity minerals used to thicken paint, improve durability, and reduce cost.

- also called inert pigments, they serve as a base without affecting color.

Calcium carbonate

- most widely used of the extenders pigments

- used throughout the range of water and solvent based paints for both interior and exterior application.

Silica

important group of extender pigments used in various particle sizes as a flatting agent to reduce gloss and improve flow in coatings. It's effective but relatively expensive.

Clay

are added for good dispersion, suspension, and opacity in water-based paints, but they offer poor weather resistance.