The essentials
- Face weight measures pile fiber in ounces per square yard and excludes the backing, but a higher number does not guarantee quality on its own.
- Density, which describes how tightly fibers are packed, matters most in busy rooms because packed fibers support each other and resist crushing and matting.
- Nylon leads on durability and resilience, polyester and triexta on stain resistance, olefin on moisture resistance, and wool is natural but moisture sensitive.
- FTC labeling rules require generic fiber names, country of origin and the responsible marketer on the label, with hang-tags pointing you back to it.
- The Carpet and Rug Institute advises choosing color, construction and cushion together based on traffic, sunlight and who uses the room.
A carpet salesperson talks in shorthand: face weight, twist, triexta, cut and loop. The words are on every sample label, and together they predict far more about how a floor will hold up than color or hand feel do. Learning what they mean takes ten minutes, and it lets you compare carpets on their merits instead of taking a number on faith.
Pile Terms: How the Surface Is Built
Pile. The visible yarn surface you walk on. Everything else, including the backing, sits underneath it.
Cut pile. Yarn that has been sheared so the loop ends are exposed, producing a soft, even surface.
Loop pile. Yarn left in uncut loops. It wears hard and hides vacuum tracks, which suits busy rooms.
Cut and loop. A single carpet combining sheared and uncut yarn to build texture and pattern into the surface.
Pile style changes how the numbers on a label should be read. Loop-style Berber carpets often carry lower face weights than plush cut-pile styles, and a Berber with the lower number can still outlast the plusher carpet because fiber and construction differ. Compare face weight only between carpets built in a similar way.
Fiber Terms: What the Yarn Is Made Of
Nylon. Durable and resilient, it springs back after footsteps and furniture compress it. That makes it a common pick for stairs and hallways.
Polyester. Brilliant color and a soft feel, with generally better stain resistance than nylon. It is less durable, so it fits rooms with lighter traffic.
Triexta. A newer synthetic whose durability and stain resistance rival nylon. It is partially made from corn sugar and suits homes with children or pets.
Olefin. Also sold as polypropylene. It resists moisture, which makes it a candidate for basements and outdoor spaces, though it is less plush than nylon or wool.
Wool. A natural fiber with a rich, plush feel. It is durable and naturally stain resistant, but it is sensitive to moisture and needs more careful cleaning than synthetics.
The fiber sets the ceiling on performance. No construction number can rescue a fiber that is wrong for the room.
The Numbers: Face Weight, Density and Twist
Face weight. The weight of the pile yarn in ounces per square yard, not counting the backing. More fiber can mean a plusher feel, but a higher number alone does not mean better quality.
Density. How tightly the fibers are packed together, driven by both face weight and pile height. Dense carpets resist crushing and matting because packed fibers support one another.
Twist. The number of turns in the yarn, usually counted per inch. More twist helps yarn hold its shape and keeps the surface looking good over time.
Finger test. Bend a sample backward and look at the backing. If the backing is easy to see, density is low; if tightly packed fibers hide it, density is high.
| Term | What it measures | What it tells you |
|---|---|---|
| Face weight | Pile fiber weight per square yard, excluding backing | How much fiber is in the pile, best compared within similar construction |
| Density | How tightly the fibers are packed | Resistance to crushing and matting under traffic |
| Twist | Turns in the yarn per inch | How well the yarn holds its shape and appearance |
None of these numbers guarantees durability on its own. Fiber type, pile style, padding, installation and the conditions in your home all play a role, so weigh them together. If a specification is missing from a sample, ask the retailer for it rather than assuming a bigger number wins.
Pro tip
Two carpets with the same face weight can wear very differently. A tall, loose pile can post a big face weight number and still mat down in a hallway, while a shorter, tighter pile holds its look for years. For busy rooms, put density near the top of the list.
Labels, Ratings and Warranties
Generic fiber name. Federal rules enforced by the FTC require labels to identify manufactured fibers by generic name. The label must also state the country of origin and the manufacturer or business responsible for marketing the product.
Hang-tag. A swing tag can carry fiber names, trademarks and performance claims without listing the full fiber content. FTC rules require it to point you to the label for the complete picture.
Green Label Plus. A Carpet and Rug Institute program that identifies carpet, adhesive and cushion products designed to be among the lowest emitting on the market.
Seal of Approval. A separate CRI program that certifies carpet cleaning products, equipment and service providers.
Warranty language sits on top of all this. Actual performance depends on the fiber, pile design, installation and household conditions, so read what a warranty actually covers before you count on it. The CRI also recommends periodic professional cleaning to keep carpet performing and looking its best, and some warranties spell out cleaning requirements, so check those details before you buy.
Pad and Cushion Terms
Cushion. The pad installed beneath the carpet. The CRI advises choosing the color, construction and cushion together based on how the room is used, and its Green Label Plus program covers cushion as well as carpet.
Installation matters as much as the pad. The CRI’s residential and commercial installation standards, which the industry updated in 2015 to address planning and subfloor preparation, are the reference installers follow. Good carpet over a rushed installation will not perform the way the sample promised.
Stain and Treatment Claims
Stain-resistant fiber. Some resistance is built into the fiber itself. Polyester and triexta generally resist stains, and wool is naturally stain resistant, while nylon earns its reputation through durability and resilience.
Antimicrobial treatment. An additive that some manufacturers build into carpet as a preservative and others skip. These treatments carry regulatory requirements, and regular cleaning still does the main work of controlling contaminants indoors.
Questions to Ask at the Store
Start with the room, not the sample rack. The CRI suggests working through these questions before you buy:
- How much foot traffic will the carpet get, and will the room be the center of family activity?
- Does the room get direct sunlight?
- Will an older adult use the space?
- Will the carpet sit over heated flooring?
- Will it live indoors, outdoors, or somewhere in between, such as a screened porch?
Then ask about each carpet on your shortlist: which fiber it uses, its face weight, its density, its pile style, and what the warranty covers. If any of that is not on the label, ask. A dealer who can answer those questions quickly is a good sign the rest of the purchase will go well too.
Related guides
- What Is Luxury Vinyl Plank Flooring? A Plain-English Guide if you want to weigh carpet against a popular hard-surface alternative.
- Do Dark Floors Really Make a Room Look Smaller? for sorting color myths from reality while you pick a shade.
- Flat, Eggshell, Satin or Gloss? How to Choose a Paint Sheen for choosing wall finishes that work alongside your new floor.
Common questions
What matters more, face weight or density?
Density usually matters more, especially in traffic. A carpet with tall, loosely packed fibers can post a high face weight and still crush and mat, while tightly packed fibers support one another underfoot. Compare both, but give density more weight for hallways, stairs and family rooms.
Does a higher face weight mean the carpet will last longer?
Not by itself. Fiber type, density, twist, pile style, padding and installation all affect longevity, and a lower-face-weight carpet can outlast a heavier one built differently. Compare face weight only between carpets with similar construction.
What does Green Label Plus mean on a carpet label?
It is a Carpet and Rug Institute program that identifies carpet, adhesive and cushion products designed to be among the lowest emitting on the market. The CRI runs a separate Seal of Approval program that certifies cleaning products and equipment.
Should I trust the claims on a carpet hang-tag?
Hang-tags can carry fiber names and performance claims, but under FTC rules a tag that does not disclose the full fiber content must direct you to the label for the complete picture. Treat the hang-tag as a preview and the label as the record.
This guide is general information, not professional advice. Follow the manufacturer’s instructions and your local building codes, and hire a licensed professional for electrical, gas, structural or roofing work.