What's in the Can?
All paints are made up of pigments suspended in a medium that, once the paint has been applied, forms a solid film that binds the pigments together and sticks to the painted surface. In water-based paints, the medium is made up of water and synthetic resins. In oil-based paints, the medium is a mixture of oil and natural or synthetic resins.
What determines the final appearance of paints is the proportion of pigment to resin. Matt finishes contain the most pigment and therefore have the greatest covering capacity. Gloss finishes have a higher proportion of resin. Generally, the higher the gloss, the more durable the finish is.
Various other additives affect the qualities of paint, such as whether it's liquid or non-drip, how quickly it dries, and its shelf-life.
Cheap paints usually contain a lower proportion of pigment, and therefore several coats may be needed to achieve adequate coverage - so they don't necessarily save you money and may cost you far more in terms of time.
