Aside from the painter (you), a good paint job is influenced by several factors: the condition of the object being painted, the paint, the applicator and the temperature.

Enough can't be said about using the right paint for the job. Many people believe that one type of paint can be used on all surfaces. But, in fact, in most cases the paint that is best used on interior doors is different from that which is ideal for interior walls.

The most widely used paint for interior walls in the home is latex flat. It is water based, easy to apply and can be cleaned up with soap and water. This is in sharp contrast to alkyd, or oil-based paint, which we suggest using for doors, windows, trim and wet areas such as bathrooms, the kitchen and laundry. Oil-based paint is more abrasion-resistant than latex paint. It is more durable, is easier to clean and, when properly applied, offers a stunning finish.

Many do-it-yourselfers choose not to use oil because, unlike latex, cleanup involves mineral spirits. Also, many find oil-based paints more difficult than latex to work with. While this may be true to some extent, we believe that its benefits far outweigh its negatives.

Equally important to the choice of paint is the applicator used to spread it. Latex paint (flat wall or enamel) is best applied with a synthetic brush made from nylon, polyester or a combination of the two. Oil, on the other hand, should be applied using a natural Chinese bristle brush. The solvents used in oil-based paints will break down the fibers of a synthetic brush. Conversely, the water in latex paint will bloat the strands of a natural brush and will make painting difficult, resulting in an inferior finish.

The size of a brush will also have a great deal to do with the ease of application and the appearance of the finished product. We like to use a 3 to 4-inch brush for large areas and a 2 to 3-inch angled trim brush for trim hard-to-access areas. A smaller brush can be used for finer work.

If you're a regular reader of this column, you are familiar with our painting credo: At least three-quarters of a painting project is preparation. For example, prior to painting an interior door, any loose or chipping paint should first be removed using a paint scraper and followed by a thorough sanding.

Low spots, dings and dents should be filled using a high-quality interior vinyl spackling compound applied with a putty knife. Once the spackle has dried it should be sanded. More than one application of spackle may be required since it is prone to shrink. When dry the spackle should be sanded a final time.

After patches have been made, the entire surface of the door should be lightly sanded using 120 to 150 grit paper. Once the sanding is completed, all of the sanding dust should be removed using a vacuum or a tack cloth. A dry paint brush can be used to remove dust from corners and other nooks and crannies.

The door now is ready for a coat of primer. We suggest using a high-quality oil-based primer. Most oil-based paints are a bit thick or gummy, hence it's a good idea to add an ingredient that will help the paint flow more easily. Only a light coat of primer is needed. While the prime coat will help cover the previous coat of paint, its primary purpose is to improve the bond between the old and new coats.

Most primers dry in a short period of time and can be sanded after a few hours. A light sanding with a 150 to 220 grit paper is enough to achieve a smooth, uniform finish onto which the first coat of finish can be applied. After sanding, the door again should be rendered dust-free using a vacuum or tack cloth.

For the finish coat we recommend using a high quality interior oil-based semi-gloss enamel. Semi-gloss refers to the sheen. It is shinier than a flat or an eggshell, but not as shiny as a gloss or high-gloss. Semi-gloss reflects light nicely and is easy to clean.

As with the primer, the finish paint may be a bit on the thick side and might need an additive to make it easier to apply. Thick paints are gummy, hard to apply and will leave a grainy and uneven surface. A thin coat of paint will flow more easily, resulting in a smooth, glasslike finish. When a second coat is required, lightly sand the first coat of finish before applying the second, and do a thorough job with a vacuum or tack cloth. This again will improve the bond between the coats of paint and enhance the finished product.

Although we used doors as the example, the process is the same for windows, baseboard, crown mold, chair rail and other interior painted trim.