PADDING
Padding is primarily meant to keep your carpeting from disintegrating on contact with air and comes in many type and thicknesses. Since padding will have an impact on how long your carpeting lasts, it pays to find the right kind for your carpeting.

Felt padding is made of animal hair or jute (the glossy fiber of certain Asian plants—Corchorus olitorius and C. capsularis—for all you botanists). It is quite pricey and works well with woven carpets.

Urethane foam is the most common form of padding and comes in many densities. When shopping for it do the Mr. Whipple and squeeze the Charmin out of it to check how dense the product is. If it flattens easily between your fingers, there isn’t much there but air.

Rebond is recycled urethane leftovers scrunched together. It’s available in your basic plethora of thicknesses and you should shop for it as you do for urethane foam. In other words: squeeze away.

PILES OF STYLE
There are tons of wall-to-wall carpeting styles to pick from:

Berber
Invented by the Berber of Seville (joke), Berber carpeting is made up of rows of fabric loops that can all be one length or different lengths. It’s tough stuff, too. Keep in mind that you will see the seaming in Berber more than in other styles. It also crushes underfoot and doesn’t rebound well from foot traffic.

Cut-Pile
Cut-pile is created by lopping the tops of carpet loops and creating two separate yarn tufts. There are a variety of cut-pile styles: Plush, Saxony, Velvet and Cut and Loop. Velvet is thick and cushy but it shades, or leaves footprints after having been walked on. Saxony fibers (twists of fiber) behave as unruly split ends and have to be heat set (ouch) like your perm. Plush is what is probably under your feet at the moment (a common flat cut) and Cut and Loop is just what it says.

Designer Mark McCauley, ASID, is a carpet expert in the Chicago area.