Paints are more than just a substance which color your walls. Most accurate scientific description for a paint is a liquid composition which consists of color pigments and is applied on a substrate in a thin layer with the primary purpose of protecting, coloring, decorating and providing a texture to an object. Paints are available in a number of colors and in different types and usually is in the liquid form. A paint basically consists of pigment, Binder (resin), solvent and additives.
Pigments are small solid particles which enhance the appearance and increase the durability of a paint. They basically come under two types, Prime Pigments, and Extender Pigments.
Titanium Dioxide (white), Chrome Green Oxide, Red Iron Oxides are typical prime pigments which provide whiteness and color and have hiding properties. Titanium Dioxide is a popular Prime Pigment. Though it is costly, its characteristic of hiding and providing whiteness to dry as well as wet paint makes it the most operational prime pigment.
Extender Prime Pigments gives extra thickness to the paint. Though these pigments only contribute to the dry paint they are necessary to control the glossiness of the paint.
Paint binder is a major ingredient which provides the binding effect which holds the paint pigments together and is responsible for a paint coating/ layer on the surface after drying. A binder provides the paint with adhesion ability, resistance against scrubbing, fading, and washability. Binder includes a Natural or a synthetic resin. Water based paints use acrylic paints which most commonly consist of linseed oil. These paints provide great adhesion and give a superior finish. Solvent Based resins are normally used in enamel paints.
Solvents act as a carrier for the pigment and the binder, whether solid or liquid, to create a paint coating. The solvents may be organic like mineral turps or inorganic like water. In oil based alkyd paint the solvent is typically a paint thinner while in latex paint it is typically water. The paint performance depends upon the ability of a solvent to hold the solid particles together.
Additives increase the overall paint performance. Though the additives are added in a small amount, they enhance the resistance ability of paint against mould, brushing, sagging, and scuffing to a greater extent.
Additives include thickening agents, surfactants, biocides, co-solvents cyclists, emulsifier, UV stabilizers etc. Additives modify paint adhesion, flow properties and overall the finished appearance.
These all four ingredients are necessary to form a top quality paint to perform perfect painting job.