A chip in your vehicle's paint isn't just a cosmetic annoyance. If left untreated, it can cause damage to the car's body and require a major repair job.

For this reason, it's usually a good idea to repair chipped paint as soon as you notice it. You may have to buy a few materials to do so, but it will be less costly than taking it in for body work.

James E. Duffy and Robert Scharff, authors of the 2004 textbook "Auto Body Repair Technology," say chips in the paint are usually caused by impacts from stones or other road debris. They'll also appear on the side of your vehicle if the person parked next to you opens their door carelessly and hits your car. For these reasons, chips are most common on the doors, front edge of the hood, front bumper, and the fenders and quarter panels behind the rear wheels.

A paint chip can cause more damage to the vehicle by allowing rust to form. Don Taylor, author of the 1998 book "Automotive Detailing," says chips can create an opening to the vehicle's metal body. Even if it does not penetrate all the way to the metal, the paint coat is designed to take the brunt of the elements and the underlying primer coat will not be able to provide as much protection to the body. Chips can also weaken some components by exposing them to the sun's ultraviolet radiation.

Taylor says it is sometimes possible to get the problem fixed at no cost. Your vehicle's rust-through warranty might cover the repair of any paint chips. If you don't have this protection, however, you can pick up a few supplies to complete the work yourself.

Family Handyman Magazine says chips are easiest to repair when they are small and new. Once the exposed metal starts to rust, it will be a more time-intensive process to complete a fix.

The work is best done in moderate temperatures of 50 degrees or more. Vincent Ciulla, writing for About, says it should be done early in the day during the warmer seasons to prevent the paint from drying too quickly.

There are a few different ways to find your exact paint color. Paul Wright, writing for Popular Mechanics, says it is often found on a sticker on your door. Family Handyman says it might also be located under the hood. Checking your vehicle identification number with your dealership's records can also help you determine the right color.

You should be able to find a small bottle of the right kind of paint at an auto supply store. A bottle of automotive primer will also come in handy. Ciulla says you should make sure to get the automotive primer rather than a spray-on primer typically used in home improvement projects.

Wash the car to get rid of any dirt and grime around the chipped area. You should do a deeper clean around the chip with denatured alcohol or another finish-friendly material that will remove any wax or grease. Ciulla suggests using masking tape around the chip and applying the material with a clean cloth instead of a paper towel.

For small chips, apply a dab of primer first. Family Handyman says the butt end of a paper match is especially useful for this purpose as well as the application of paint. The primer should dry for at least half an hour.

Larger chips should be thoroughly cleaned out before the primer is applied. Wright suggests using tweezers to remove any debris or flaking paint around the edge of a larger chip. You should also use isopropyl alcohol to remove any rust and carefully sand the edges to prevent further flaking.

Before applying the paint, put a little bit on a piece of paper to make sure it will match your vehicle's paint job. This test will also help you determine how much paint to apply to the chip. Use the applicator to smoothly paint over the primer, and clean up any spills with a small amount of lacquer.

Taylor says the paint will shrink as its solvents evaporate, so several thin coats may be necessary. Allow about a day between coats to give the paint sufficient time to cure.

If the paint is at a higher level than the rest of the paint job, it can be sanded down. Be careful to only sand the new paint to avoid damaging the existing coat. An application of clear coat will also help to camouflage any differences between the new paint and the old.

As a final step, add a polishing compound with a soft cloth. The compound can then be washed off. Wright says the repair should be given about a week to cure before you wax your car.

This repair will leave your car better prepared against the elements, and it will also eliminate just about any sign of the danger. Although it might not be entirely seamless, the repair should be enough to not be noticeable unless you're looking for it.