Before the advancements in paint technology that began during World War II, all enamel paints were oil-based paints, which created a hard, exterior and glossy opaque surface. After the introduction of water-based latex paints in the 1940s along with the introduction of plastic paint emulsions -- acrylics -- a decade later, enamel paints nowadays signify both water-based and oil-based paints with a hard, flat, semigloss or glossy appearance.
The First Paints
The world's ancient ancestors -- Romans, Greeks and Egyptians -- used lead treated with vinegar or wine to make some of the first types of paint. In the centuries that followed, organic chemicals such as turpentine from pine resin, linseed oil from flax, and organic, colored pigments suspended in oil were added to the white-lead paste to create paint. While these early oil-based paints covered well, had good spreadability and sticking power, they also caused people to die from lead poisoning through ingestion, respiration or skin absorption. Nowadays, paints with lead that exceed recommended Environmental Protection Agency’s safe amounts are banned in the United States.
The Three Components of Paint
Paint contains three components: the pigment, or color, the binder, and the carrier. What pigment does is obvious: It adds the color to the paint. The binding agent also sometimes becomes the paint’s name: acrylic for the acrylic emulsion, and, oil-based or alkyd, also known as resin, for oil-based paints. The binder holds the paint ingredients together. The carrier -- the solvent such as water or oil -- spreads the binder to allow the paint to flow and coat the item.
World War II caused a shortage in linseed oil and the solvents used to make oil-based enamel paints. This shortage propelled chemists Otto Rohm and Otto Haas, founders of a chemical company acquired by the Dow Chemical Company in 2009 to create acrylic paints in the 1950s, which didn’t take off with the public until the 1970s. Prior to the arrival of acrylic paints, the Sherwin-Williams company created a synthetic rubber, water-based paint called latex paint during the war years.
Oil-based enamel -- also called solvent-based or alkyd paint -- contains unstable organic compounds, which creates the strong odor associated with enamel paints during drying. Oil-based paints represent about 20 percent of the paint products on the market today, with water-based paints making up the difference. The VOCs in oil-based paint make for a smoother application, adhesion and drying, but they release harmful fumes into the air and environment as the paint dries.Other characteristics of oil-based enamel include its resistance to high temperatures, the ease with which you can clean its painted surfaces, and its overall durability.
Oil-Based vs. Latex Enamel
Oil-based enamel paints offer a superior product on exterior surfaces that require extra durability, but cleanup requires mineral spirits or turpentine solvents. Many crafters and woodworkers prefer oil-based enamel because they like how it flattens out as it dries to hide paintbrush marks. Woodworkers particularly like it for high-traffic furniture pieces because it is harder to chip than water-based acrylic paints.