There is a small tag on your sofa with a single letter on it, and that letter decides whether the piece survives cleaning. Most people have never looked at it. A fair number of ruined sofas start with a rental machine, a bucket of hot water and a fabric that should never have been wetted.
Upholstery cleaning codes are the fastest way to avoid an expensive mistake. Four letters, each meaning something specific, and knowing yours changes what you should do next.
Where the tag actually is
Three usual places. Under a seat cushion, on the underside of the deck the cushions sit on, or on the frame underneath the piece, which means tipping it over.
On sectionals, each section may carry its own tag, and they are not always identical, particularly on pieces assembled from a manufacturer’s modular range.
If the tag has been cut off, the piece has been reupholstered, it came from overseas, or it is old enough to predate the convention, you will not find one. That is a common situation and it is handled differently, covered further down.
The four codes
W: water based cleaning agents. The fabric can be cleaned with water based products. Most synthetic upholstery falls here: polyester, olefin, nylon, most microfibers, and the majority of what has been sold in the last twenty years.
S: solvent only. Dry solvent cleaning agents only, no water. This is the code that matters most and the one people ignore most often. Water on an S code fabric can produce permanent rings, shrinkage, texture change and fiber distortion.
WS: either. Water based or solvent, whichever suits the soil. The most forgiving code, and it still does not mean unlimited moisture.
X: vacuum only. No liquid cleaning of any kind, water or solvent. Vacuuming and light brushing only. Certain velvets, some delicate jacquards and a range of decorative fabrics carry this code, and it is not a suggestion.
One thing worth understanding: these codes come from a voluntary furniture industry labeling convention, not from a legal standard. They tell you what the manufacturer will stand behind. They are a strong guide and not a guarantee, and a good technician still tests.
Why the S code is the one that catches people
Because of what is usually behind it. Rayon and viscose are the biggest culprits, and they are everywhere in mid range upholstery because they look like silk and cost a fraction of it.
Both are cellulose based fibers, and both lose a substantial amount of their strength when wet. Wet them and they can distort, shrink, develop permanent watermarks and lose their surface texture. A viscose blend that has been water cleaned by someone who did not check the tag often cannot be recovered by anybody.
Silk and linen sit in similar territory. Silk marks with water rings readily. Linen shrinks and creases in ways that do not come out.
On these fabrics a solvent based dry cleaning method is not a lesser option. It is the only option, and it is the reason professional upholstery work carries more than one system on the truck.
W does not mean do it yourself
This is the second half of the problem. People find a W, hire a machine and go to work, and four things go wrong.
Over wetting. Rental machines put down far more water than they recover. Water reaches the cushion core and the frame, and a foam core holding water takes days to dry, smells while it does, and can push discoloration back up through the fabric as it dries.
Water rings. Cleaning a spot rather than a full panel leaves a boundary where the wetted area dried differently from the dry area. The ring is often more visible than the original mark.
Cellulosic browning. On fabrics containing natural fibers, or with a jute or cotton backing, prolonged wetness draws tannins and other compounds to the surface as it dries, producing a yellow brown discoloration. It is a chemistry problem, not a soil problem, and it appears a day or two after the cleaning looked fine.
Frame and dye bleed. Some frames stain through when soaked. Some dyes migrate when wet, particularly on darker fabrics and on pieces where a decorative trim runs against a lighter panel.
When there is no tag
Which happens constantly. The process a technician follows is straightforward and it is worth knowing so you can tell whether anyone is actually doing it.
Fiber identification first, by feel, by construction, by appearance, and where necessary by testing a single thread from a hidden area.
Then colorfastness testing. A small amount of the intended cleaning solution is applied to a hidden area, blotted with a white cloth, and the cloth is examined for dye transfer. Repeated in a second location, because a patterned fabric can be fast in one color and not in another.
Then a test clean in a concealed area, allowed to dry completely before any conclusion is drawn, because most of the failure modes above only appear after drying.
If a technician wants to start cleaning your sofa without doing any of that, that is the moment to ask questions.
The parts of the sofa nobody thinks about
The face fabric is only one component. Cushion cores hold moisture and are slow to release it. The decking under the cushions is often a cheaper, less stable material than the visible fabric. The dust cover on the underside is thin and tears easily. Trim, piping and buttons are frequently a different fiber from the main body, with different tolerances.
Any of those can be the thing that fails, which is why controlled moisture and immediate recovery matter more on upholstery than on almost anything else in a house.
What Anchorage adds
Two useful things and one problem.
Winter indoor air here is extremely dry, often in the teens for relative humidity through the heating season, so upholstery dries faster than it would in most of the country. That is genuinely helpful, and it means winter is a sensible time to have soft furnishings cleaned.
The problem is use. People are inside for months. Sofas in Anchorage take a heavier annual load than sofas in milder places, and homes with a wood stove add fine soot to the mix, which settles into fabric and dulls color long before anything looks dirty.
Body oils are the other slow accumulator, concentrated on headrests and arms, and they are what turns a fabric gray in a pattern that follows where people sit.
Getting it right
Find the tag before you do anything. If it says S or X, do not put water on it under any circumstances. If it says W or WS, you still want controlled moisture and proper extraction rather than a rental machine.
The general ground covered on upholstery is in everything you need to know about upholstery cleaning, and households with pets and children have their own set of considerations in upholstery cleaning tips for homes with pets and kids. Leather is a different material entirely with its own rules, set out in the dos and donts of leather sofa cleaning.
Our upholstery cleaning service carries both water based and solvent systems, which is what the code range requires. Once a piece is clean, fabric protection buys response time on the next spill. More upholstery writing sits in the upholstery archive, and you can schedule a service visit if you want a piece identified and tested before anything is cleaned.
Frequently asked questions
Where do I find the cleaning code on my sofa?
Check under a seat cushion first, then the underside of the deck the cushions sit on, then the frame underneath, which means tipping the piece over. On a sectional, check each section separately, because they do not always carry the same code.
What does an S code mean?
Solvent cleaning only, no water. It usually indicates a fabric containing rayon, viscose, silk or linen, all of which can shrink, distort or develop permanent watermarks when wetted. Rayon and viscose in particular lose a substantial amount of their strength when wet, and damage to them is often not recoverable.
Can W code fabric be steam cleaned at home?
It can be cleaned with water based products, but a rental machine puts down more water than it recovers. That leads to saturated cushion cores, slow drying, water rings around spot cleaned areas and, on fabrics with natural fiber content, brown discoloration that appears a day or two later as the piece dries.
What if my sofa has no cleaning tag?
The fiber gets identified by feel, construction and appearance, and where needed by testing a thread from a hidden area. Then colorfastness testing with the intended solution and a white cloth in at least two concealed locations, followed by a test clean allowed to dry fully before any decision is made. A tagless piece is normal, not a problem.
What does an X code mean and can anything be done?
Vacuum only, with no liquid cleaning of any kind. Regular careful vacuuming with an upholstery tool and light brushing to lift the pile is the full extent of what should be done at home. Anything beyond that should be discussed with a technician who can inspect the piece and tell you honestly whether there is a safe option.