I have no idea how to get down feathers from a duck, but Wilford Lieber does. The feathers come in clusters from the breast and thighs. Even so, the goose is always preferable to a duck.

He can also easily discern with the help of a microfiche reader which feathers belong to a goose, which to a duck and which to a chicken.Chicken feathers, by the way, are inferior.

Once that is done, he can separate the feathers from the down and determine whether a given product - a jacket, a comforter, a mattress, a pillow - have the acceptable minimum standard of down - 70 percent - as established by the Federal Trade Commission.

He can measure the cubic inches per ounce of down in a cylinder, and declare whether a product has desirable "fill-power" - 500-600 is excellent. The greater the fill-power, the greater the comfort.

He can measure the water content to make sure that it is low enough to discourage the growth of bacteria, which would in turn destroy the product.

He can measure the oil and fat in the product and determine whether acids and dirt particles were properly washed out. The right balance of oil and fat are needed to repel water, while too much creates an odor.

But don't talk to him about polyester. People sweat in polyester jackets, while down absorbs and releases moisture. Polyester does dry more quickly if wet, but it lacks "the comfort range" of down. Although a few people are allergic to down, "there has never been a product yet that is better than down," says Lieber.

"Even though it costs $30-$40 per pound today, the life expectancy of goose down in a product is 25-30 years," says Lieber.

Wilford Lieber is the president of the International Down and Feather Testing Laboratory, located in Salt Lake City. He and his wife, Mary Jean, and their six employees operate the best known and most reputable down lab in the world. It has been a going concern since 1978.

All of the major manufacturers and sellers of down products send their stuff to the Liebers for a look - Lands' End, Pillowtex, Northern Feather, Sears, J.C. Penney, etc. (more than 250 of them in the United States, Canada, Europe and the Orient). Even though most of them have their own in-house labs, they need that objective, outside opinion to certify the high quality of their product.

Lieber's lab serves an important need - to discourage cheap products and pressure all companies to do better work.

If you think Wilford Lieber has a soft job, think again. He continues to give international seminars in down and feather testing in China, Japan, Korea and Europe. He says China supplies most of the down in the United States, but Poland produces the best goose down. An incredible 95 percent of the down products are manufactured overseas.

Lieber was born in Basel, Switzerland, and trained as a chemist, working six years with Roche Pharmaceutical before emigrating to the United States and settling in Salt Lake City because of his conversion to the LDS Church. He worked as assistant state chemist and as director of laboratories for the Utah Department of Agriculture.

Gradually he became involved in down testing and was asked by the down and feather industry to establish a private lab to help them verify the integrity of their products. They approached him where he lives, because integrity is his most important business principle - for both the consumer and the industry.

He then developed a method of analysis for feathers and down that has become the worldwide standard. It has been adopted by the American Society for Testing Materials, the International Feather Bureau in Frankfurt and by every state in the union except California.

I went to the Down and Feather Testing lab ignorant of its work, unsure of how to harvest down from a duck. I still can't tell you how, but I know that it is impossible to fluff polyester. It IS possible to fluff down - if you get down from a duck or a goose. Besides, we can all sleep better - knowing that Wilford Lieber is on the job.