The article on dressings for summer salads in the Thursday, July 24 Food section contained an error. As a general rule for making dressings, the ratio of oil to vinegar should be 3 to 1.

WE'VE BEEN duped. The manufacturers would have us believe that their orange snake oil in a bottle is French dressing, while the amber liquid flecked with dabs of green is Italian. Don't take it anymore! Why pay dearly for a product that can be duplicated at home in minutes, and will taste infinitely better than the chemicals, artificial coloring and gums of the bottled versions?

Start your salad dressing homework with a thorough knowledge of the nature of all dressings: The bottom line is oil and vinegar. This is, perhaps, an oversimplification, since there are many embellishments on the basic vinaigrette theme, any one of which alters its character considerably.

First, there is oil: olive, peanut, corn, walnut, safflower, vegetable. And of vinegars there are white wine, red wine, champagne, cider, tarragon, raspberry. Or, you may omit the vinegar and replace it with lemon juice or wine. There! You've just modified your dressing without the addition of a single other ingredient.

You may play the matchmaker and find a perfect marriage of oils or you may discover them already "blended" in most Mediterranean specialty stores. These "blends," which come in gaily decorated tins, generally consist of 10 to 25 percent olive oil and 75 to 90 percent other oils. They are inexpensive and excellent.

The proportion of vinegar to oil is germane to the ultimate taste of a salad dressing. The rule of thumb is 1 part oil to 3 parts vinegar. Acceptable variations range from 1 to 2 through 1 to 5. These ratios are based on the dictates of your palate, the particular combination of greens your dressing will grace and the strengths of oils and vinegars you have chosen.

Obviously, the addition of salt and freshly ground pepper is a must, and once accomplished, you have a basic vinaigrette. Now comes the fun part. Add garlic, cream, egg, herbs, mustards, spices . . . the list is endless. Experiment with your own combinations and be amazed at the diversity of tastes you discover.

Garlic is important and therefore worthy of discussion. It is, unfortunately, misunderstood. The first thing to learn is that garlic, raw, is more potent than garlic, cooked. What happens to it next -- bruising, chopping, mashing or pressing -- dramatically affects the flavor of your particular vinaigrette.

If you are garlic-sky, bruise the clove by hitting it with the flat of a knife, to wrest but a mite of its potential strength. Now is the time to remove the skin which will come off easily. Massage the interior of a wooden salad bowl with the same clove, or drop it in your dressing to impart a mere hint of taste. You may want to extract more flavor by chopping it.

Maximum flavor is obtained by smashing it flat as a pancake and reducing it into a paste. This is done with a flexible knife, such as a sandwich spreader, and a sprinkle of coarse salt on the clove. The salt acts as an abrasive, eroding the woody fibers of the garlic, as the knife simultaneously scrapes it into a pulpy mass.

This technique is akin to the action of a garlic press but its effect is more benign. "Pressing" garlic results in a juice which, to my tongue, has a metallic flavor and is too strong. Besides, cleaning the press is a drag.

To coin a phrase, "variety is the spice of life" and this may well be your justification for the dozen bottles monopolizing your refrigerator.Fight the urge to succumb to supermarket madness. Use your imagination. Prepare one basic vinaigrette each week, using sundry oils and vinegars. Decant enough dressing for dinner and change its personality by the addition of other ingredients.

Zesty or mild, a dressing must have enough assertiveness to make its presence felt. Look for a "catch" in the back of your throat s a sign of its authority. If the dressing is too sharp, add more oil; if too "oily," add more salt.

As in wine-tasting, it becomes increasingly difficult to trust your taste buds after 1 or 2 spoonfuls, so cleanse your palate with a cracker. Then taste again. Once you've arrived at the "right" taste, you'll know it. PIQUANT DRESSING (8 to 10 servings) 1 whole egg 1 tablespoon grated parmesan 1 garlic clove, crushed 1 1/2 teaspoons Dijon mustard Salt and pepper, to taste 1/2 cup safflower oil 1/4 cup lemon juice

Mix the ingredients together. Remove the garlic before serving. HONEY POPPYSEED DRESSING (16 to 20 servings) 1 cup honey 1 cup peanut oil 1 cup olive oil 2/3 cup cider vinegar 1/4 cup lemon juice 1/2 small onion, chopped 1 small slice fresh ginger, peeled and chopped 2 teaspoons dry mustard Salt and pepper to taste 2 tablespoons poppyseeds

Combine the honey, oils, cider vinegar and lemon juice. Add the onion, ginger, mustard and salt and pepper. Gently stir in the poppyseeds so as not to break them. CAPER DRESSING (8 to 10 servings) 1/4 cup capers, drained and halved, if large 1/2 cup corn or olive oil 1/4 cup tarragon vinegar 2 tablespoons dry white wine 1/2 teaspoon dry mustard Salt and pepper to taste

Whisk ingredients together or shake in a screw-top jar. BLUE CHEESE DRESSING (10 to 12 servings) 3/4 cup oil, all olive or olive and vegetable oil 1/4 cup lemon juice 2 tablespoons finely chopped green pepper 2 tablespoons chopped parsley 1 tablespoon Dijon mustard 1 clove garlic, mashed Freshly ground black pepper 1/3 cup crumbled blue cheese

Whisk together all of the above ingredients except the cheese. When well blended, stir in the cheese. MINT DRESSING (10 to 12 servings) 1 cup blended oil 1/2 cup cider vinegar 1/2 cup fresh chopped mint leaves 1 garlic clove, mashed 1/2 teaspoon fresh ground pepper 1 teaspoon sea salt 1 teaspoon honey

Shake in a jar or whirl in a food processor.