Sheets and pillowcases are normally made of linen, cotton, or a cotton-polyester blend. The four principal varieties of cotton, are American upland, Egyptian, pima, and sea island (the finest). Any of the four can be woven into four basic sheeting fabrics: flannel, muslin (a smooth, simple weave), oxford (soft, porous, and rather heavy; also used for shirts), or percale (finely combed and closely woven, easy to launder).

Whichever fabric type you choose, pay attention to thread count -- the number of threads per square inch. The higher the count, the finer the quality of the sheet. The highest count made in the United States is 310; 200 is a good standard.

The label on your linens may also mention finish: mercerized cotton has been treated with alkalis for a distinctive sheen; sanforized cotton has been preshrunk; easy-care and durable press finishes are mechanical or have chemical treatments intended to reduce wrinkling.

American bed linens come in a standard range of sizes, with minor variations from one manufacturer to the next. (The variation is only noticeable in the depth of the "box" in a fitted sheet; better-quality sheets are deeper to accommodate the new, thicker mattresses, and need less tugging.) If you plan to choose linens from outside the United States, make sure they conform to the following flat sheet sizes (don't even attempt to buy fitted sheets abroad): twin, 66-by-96 inches; full, 81-by-96 inches; queen, 90-by-102 inches; king, 108-by-102 inches.

As a general rule, you'll want three sets of sheets for your master bedroom. Make the first classic white. 

After you have your whites covered, choose additional sheets in colors that will coordinate with your bedroom's decor -- and each other. For instance from top to bottom: 1. "Rebus jacquar" set, by Pratesi. 2. "Jo" fitted and flat, Missoni, Unica Home. 3. "Tuxedo stripe" flat, Charisma. 4. Custom "savannah" fitted and flat, Leontine Linens, leontine linens.com. 5 & 6. "Rem" fitted in peacock, "nite" flat in oyster, Society, from ABC Carpet & Home. 7. "Ritz" fitted and flat, from Nancy Koltes at Home. 8. "Royal velvet" set, Homestead, from Bed Bath & Beyond. 9. "Pure comfort" fitted and flat, DKNY, from bloomingdales.com. 10. "Union square" set, Sferra. 11. "Ellington" fitted and flat from Garnet Hill.

Get adventurous by adding pretty throw pillows to the mix. Here are a few we like: 1. "Shanghai apricot" sham, Twinkle Living. 2. "Cayenne paisley" pillow, Hable Construction. 3. "Zafferano" sham, Anna Sova, from ABC Carpet & Home, 212-473-3000. 4. Silk pillow, Michele Varian, for similar. 5. "Abstract leaves" pillow, Ankasa, from Calypso Home, 212-925-6200. 6. "Petites plumes" sham, D. Porthault, from Bergdorf Goodman, 212-872-8787. 7. "Lido" sham, Olatz. 8. "Modern scallop" pillow, Vera Wang Fine Linens. 9. "Tulah" sham, Matouk, from gracioushome.com. 10. "Darcy" sham, Schweitzer Linen.

Now that the essentials are in place, feel free to circle back to any fanciful pieces that may have tempted you along the way -- sheets in a lush botanical print, a jewel-toned throw blanket. It could be just the thing to complete your trousseau. Shown here: 360-thread-count pillowcase in sky blue, Martha Stewart Collection at Macy's, macys.com; "Indigo stripe" pillow case; "Red ginger" duvet cover; John Robshaw Textiles.

Cotton is the most popular fabric for towels. Towels vary in pile height, density of loops, suppleness of yarn, and other details that determine longevity and cost.

Terry towels have a top warp in addition to the usual warp (lengthwise threads) and woof (widthwise threads), making it more absorbent. Conceivably, terry can be made from any fiber. Most terry towels are made of American Upland cotton; more expensive towels use Pima and Egyptian cottons.

Jacquard is a towel with the terry loops raised and lowered to create patterns, anything from floral designs to checks and cables.

Flat-woven towels are frequently made from subtly patterned cotton or linen fabric (unusual yarns such as chenilles and boucles are also used) and are a common choice for guest towels; they wear well but require frequent ironing.