New York ? Winter is wool weather: Wool sweaters, wool scarves, wool jackets.

You’ve worn it and your grandparents wore it. Even their grandparents wore it.

Wool has been a part of wardrobes for thousands of years. Yet no two wool products are the same because, except for cloned Dolly, no two sheep are the same. (An average-size sheep produces enough wool for three suits or 12 sweaters over its lifetime, according to The Woolmark Company, a wool textile organization based in Australia, the world’s largest wool-producing nation.)

There also are many types of weaves, finishes and sheep sources, leaving modern consumers to choose from fleece and knits, lambswool and Shetland, among other choices.

Because there are so many options, wool is a versatile fabric that can be used in a variety of climates and conditions. It also can absorb 30 percent of its own weight in moisture before it becomes damp, making it ideal for outerwear.

Some people dislike the itchiness associated with certain blends of wool; others claim to be allergic. Brenda McGahan, executive director of Woolmark, says “to avoid irritation, don’t wear hairy, woolen fabrics next to the skin. Choose a worsted wool or a wool blend.”

How do you know a worsted wool from a woolen? McGahan offers this primer of wooly words:

Woolen vs. worsted

The difference is the length of the fibers. Woolens are shorter and stand up from the fabric, giving a furry feel. Examples include tweed and Shetland. True Shetland wool comes only from islands off the northern coast of Scotland and is limited in supply. The apparel industry, however, has taken more liberal license with the word to describe other soft knitwear, much the way Champagne is sometimes improperly used as a generic term for sparkling wines.

Worsteds, which include gabardines and merino knits, have longer fibers and a smoother hand, a term used to describe what fabric feels like when touched.

Merino is made of the finest grades of wool, grades of 23 microns or finer, and extra-fine merino is 19 microns or less. A micron is equal to a thousandth of a millimeter; microns are used to measure the diameter of wool fibers. The lower the micron number, the thinner the fiber.

People have been wearing wool for its warmth for thousands of years, but companies such as J.Crew also use wool as a fashionable fabric, as seen in the sweater, coats and accessories above and below.

Worsted wool also is lighter and can be appropriate for warmer climates.

Knit

A knit fabric or garment uses yarn that has been interlaced into rows of loops, either by hand or machine.

Twill

The next most common weave, usually with a noticeably diagonal line on the cloth. Twills tends to be strong and durable.

Woven

The fabric is made on a loom by the weaving process, in which lengthwise yarns, called warp yarns, are held in place by crosswire yarns, called weft yarns.

Full-fashioned knit

Used mostly for higher quality wools, this is a knit made from panels shaped during knitting and then sewn together. Another assembly technique is known as a cut-and-sew knit, which is made of flat panels from pre-knit fabric that are then sewn together. Seams tend to be bulkier than in full-fashioned knits.

Broadcloth

A compact, elegant fabric with a smooth nap, soft hand and high luster that is usually used for coats. It is set especially wide on the loom to allow for heavy shrinkage during the fulling (compacting) process.

Challis

A lightweight, especially soft fabric made with tightly spun worsted yarns – usually in a plain weave. It used to be that challis bore a floral design, but it now includes other prints and is mostly used for scarves, blouses and dresses.

Felt

This fabric is never woven; instead, it’s made of layers of thin sheets of carded wool fibers. Heat, moisture and pressure are applied to shrink and compress the fibers. It will never ravel or fray.

Fleece

Fleece used to be a wool-only term but has been applied to other fibers as well. It describes fabric with a thick deep nap that is warm without being bulky or heavy.

** FOR USE WITH AP WEEKLY FEATURES ** In this photo provided by J. Crew, there are so many ways to wear wool. Manufacturers such as J.Crew use it as a knit, twill and woven _ all of which have different textures and appearances. (AP Photo/J.Crew)

Gabardine

With its smooth face and dull sheen, this is a popular fabric for outerwear, sportswear, suits, dresses and uniforms. It has a closely set diagonal rib on the face and a plain back.

Jersey

Recognizable with fine lengthwise wales on the front and a plain back, this is a knitted fabric that can be made in various weights.

Double knit

A wrinkle-free knit, also known as double jersey, that’s made in a variety of weights for coats, suits, sportswear and dresses. Two sets of needles are used to form fine, lengthwise wales on both sides.

Lambswool

Wool from the first shearing of a lamb that is approximately 7 months old, it’s known for being fine and soft.

Pure new wool

A term for wool direct from the sheep’s back – also known as virgin wool. The term was more meaningful in the past when woolen garments were sometimes unraveled and the yarn used to make new garments; that’s rare now.

Superfine wool

This is comparable to fine cashmere, which comes from goats. It comes from strains of merino sheep that have been developed to produce especially fine fibers.

Loden

A coarser wool that is often used for coats because it’s especially water repellent. The original cloth was made in the 16th century in the Austrian village of Loderers.

Melton

Another thick coating fabric. It is heavily napped to hide traces of the plain or twill weave. This one is named for Melton Mowbray, a town in Leicestershire, England.

Wool clothing care tips

¢ Brush after every wearing with a soft firm bristled brush.

¢ Hang clothes where they can breathe. Luxury fabrics have a resiliency and are able to shed wrinkles. They need air to help them spring back into shape.

¢ Give clothes a rest. A 24-hour rest will not only rid them of wrinkles but also will help them wear longer.

¢ Empty pockets between wearings. Heavy objects strain pocket seams and pull fabric out of shape.

¢ Treat stains promptly. Take clothes to a reputable dry cleaner.

¢ Press and clean clothing at least once a season. Be sure clothes are clean before your store them. Even the smallest of stains can invite moths.