Deciding on which colour to paint a room is only the beginning. Upon arriving at the hardware or paint store, shoppers are presented with a myriad of oil and water-based paints, glazes, varnishes and emulsions. Although the terminology and profusion of products can be overwhelming, a basic understanding of the various types of paint available will help you make the best choices for your home decorating projects.

All paint contains the following:

1. pigment (colour)
2. binder or medium which keeps the pigment in suspension and binds the paint to the wall

Water-Based Paint

Instead of lime, chalk or hide glue, modern water-based paints contain latex, vinyl emulsion or polyvinylacrylic (PVA) as well as binder and solvent. These ingredients coat the wall and produce solid rather than translucent coverage. Water-based paints are a good choice for most indoor projects because they dry quickly and produce fewer emissions than oil-based paints.

Water-Mixable Oil Paint

This product was introduced a few years ago as an alternative to the standard choices. Water-mixable oil paint is made from a type of oil that has been chemically altered to allow it to mix with water. Although the drying time for this product is longer than latex or acrylic, it does clean up easily with soap and water instead of mineral spirits. The drying time for this product is longer than latex or acrylic. This type of paint has the same rich quality finish of oil paint with a surface durable enough to be washed but should only be applied over a latex, acrylic or primer undercoat.

Water-Based Glaze

Water-based glaze (also referred to as acrylic medium) can be used on a variety of indoor projects from an artist's canvas to large wall murals and wooden chairs. Glaze is a thick transparent substance that appears milky when wet but dries to a clear finish. It helps to slow the drying process, allowing more time to create decorative finishes.

Glaze is a versatile medium; you can mix your own colours by adding acrylic paint (tubes are available in arts and crafts stores) to achieve the desired colour and intensity. The semi-translucent quality of glaze is particularly desirable when you wish to reveal an underlying surface such as wood grain.

Water-Based Varnish

After creating a unique wall effect such as a mural, it is advisable to protect it with a coat of varnish. This will allow you to wipe off dirt and dust without damaging the underlying work. Just as with water-based glaze, water-based varnish appears milky when wet and will dry to a clear finish. Caution: if you apply thick layers, the result can be a cloudy film that is susceptible to nicks and scratches. Water-based varnish is the best choice to protect water-based paints and glazes.

Oil-Based Paints

For projects that will be subjected to high-traffic and/or high moisture, oil-based paints may be your best choice. They provide rich colour with a strong, smooth finish that can be washed. Oil paints have longer drying times than water-based paints and will produce more fumes. Proper ventilation is required during application and for the next two to three weeks as the paint dries and cures.

Oil-Based Varnish

Oil-based varnish is used to form a protective coating on painted surfaces and woodwork. It tends to impart a slight yellowish hue to the painted surface and will darken with age. This should be taken into consideration when planning a project. For example, blue paint may begin to look green; red paint may appear orange. Polyurethane varnish is the most commonly available type of oil-based varnish. Cleanup and thinning require mineral spirits.

Oil-Based Glaze

This transparent medium has a creamy colour when wet and dries clear. It does not yellow as much as varnish, making it suitable for a variety of decorative projects. Oil-based glaze often requires a precise mixture of glaze, pigment and mineral spirits; check the label for the manufacturer's directions.

Rules of Thumb

Remember that in general, water-based paints should never be applied over oil-based paints and the two types should never be mixed. For example, if you are creating a coloured oil-based glaze, the pigment should also be oil paint.

Lastly, keep in mind a wise old artist's adage: fat over thin. If you are working on a project that requires many layers of paint, be sure to start with thin layers and apply the thickest layers last. Just as with wood, paint expands and contracts with heat and humidity. The thicker the paint, the more it will expand and contract. If you apply a thin layer over a thick one, the top layer may crack. To be on the safe side, thin, even layers will produce a reliable result.

Now that you know the basics of paint, varnish and glazes, there is no limit to what you can create.