History
Paint has been used since pre-history. Cave paintings dating back an estimated 40,000 years feature artwork made with soot, colored earth and animal fats. The early Egyptians formulated paint that has remained brilliantly colored to this day, using ground glass and semi-precious stone, lead, colored earth and even animal blood mixed with oils, glues and fats. Over the centuries, other colors were formulated and perfected. Artists devised their own paint recipes, which were often jealously guarded. Paint as a method of decorating buildings did not become common until the nineteenth century. Prior to that, it was expensive and time consuming to make, and decorating was more often done with stone, mosaic tile and colored plaster.
Effects
Lead and arsenic were common pigments for hundreds of years, making painting a rather dangerous profession. Lead is a naturally occuring ore and when added to paint makes it extremely durable, with color retention lasting for centuries. No synthetic alternative has been found as durable and although lead was banned from artists' and house paints in 1978 in the U.S., it is still widely used for industrial applications and for painting road markings.
Types
Historically, paint has many uses. Early uses were primarily artistic. With the advent of linseed oil as an inexpensive binder and the wider availability of mass produced pigments, it became common in the nineteenth century to both beautify and protect buildings. Linseed oil paints (more commonly known merely as oil-based paint) protected wood from the elements and old-style linseed oil paints containing lead as a color base outperforms modern day acrylic paints and lasted for decades. Today's oil-based paints are unlike the paints of 100 years ago. Acrylic (water-based) paint is used by the vast majority of painters and homeowners today. Artist's paints are also available in both oil and water bases. Milk paint, used in the 1800s for painting homes, is making a comeback today, popular for its subtle colors. Synthetic coatings like epoxy and polyurethanes were unheard of even 50 years ago and are now used in varnishes and paints for flooring, appliances, autos and industrial applications.
Function
While paint was used for decoration and art for centuries, it now performs many functions. Plaster and sheetrock walls are not only beautified by paint, they are made washable. Paint protects wood from rotting and drying out. It is used as a rust preventative on metal, from ships to buildings to outdoor furniture and signs. Paint used in parking structures and roadways directs traffic. Non-skid paint is used for steps, flooring and such diverse applications as dog agility equipment.
Time Frame
Until the mid 1800s, paint was usually made by hand for each application by artists and house painters. The advent of the mass production of pigments and the wide availability of inexpensive linseed oil as a binder prompted several companies to start manufacturing paint. The largest paint company in the world is Sherwin Williams, which started the manufacture and sale of paint for architectural applications in 1866. Now there are thousands of companies worldwide producing paint for art, buildings and industry.