Upholstery Cleaning Codes Explained (W, S, WS, X)

That little tag tucked under your sofa cushion holds the single most important piece of information for cleaning your furniture safely. It is one or two letters, and getting it wrong can leave a stain that no amount of scrubbing will fix.

What the cleaning codes actually are

Every piece of upholstered furniture made and sold in the United States carries a manufacturer’s cleaning code. The system was created by the furniture industry to tell you, in shorthand, what kind of cleaning agent the fabric can tolerate without shrinking, bleeding, browning, or losing its texture. The four codes are W, S, WS (sometimes written SW), and X.

These codes refer to the face fabric only — the material you sit on. They say nothing about the foam, the frame, or the backing. They are also a starting point, not a guarantee. A code tells you what the manufacturer believes is safe based on the fiber and the dyes; it does not account for the actual condition of your specific piece after years of use, sun exposure, and prior cleaning attempts. That is why we test before we clean, every time.

Where to find the tag (and what to do if it’s gone)

The cleaning code lives on a sewn-in tag, usually under a seat cushion, along the bottom deck of the frame, or stitched into a seam on the back. On sectionals it is often on the underside of the largest piece. The code appears alongside fiber content and the manufacturer’s name.

If the tag is missing — cut off, faded, or never there on a vintage or imported piece — do not guess. Treat it as an unknown and have it identified by fiber. An IICRC-certified textile inspector can determine the fiber type and safe cleaning method through burn tests, magnification, and spot testing in a hidden area. Guessing on an unlabeled piece is how good furniture gets ruined.

Code W: water-based cleaning

A W means the fabric can be cleaned with a water-based agent. These are typically synthetic fibers — polyester, nylon, olefin, many microfibers — that hold up well to moisture and water-based detergents. W is the most forgiving code and the one homeowners can usually do the most with between professional visits.

That said, “water-based” does not mean “soak it.” Over-wetting a W-coded fabric is one of the most common DIY mistakes we see. Too much water pushes soil and old spill residue down into the foam and padding, then wicks it back up to the surface as it dries — leaving a brown ring or stain that appears a day or two after you thought you were done. This is exactly where our low-moisture, certified-organic approach earns its keep: we use just enough solution to lift the soil, extract it, and leave the cushions dry to the touch in about an hour rather than damp for two days.

Code S: solvent-only cleaning

An S means solvent-based cleaners only — no water. These are usually natural or delicate fibers and certain rayons, silks, and some wool blends where water causes shrinking, watermarks, dye bleed, or fiber distortion. The “solvent” is a dry-cleaning chemical, not a household product.

S-coded fabrics are where homeowners get into the most trouble. Water on an S fabric can create permanent rings and color changes that cannot be reversed. We treat S-coded pieces conservatively and test in a hidden spot first. Be honest with yourself here: if your couch is coded S, this is not a job for a sponge and dish soap from under the kitchen sink. If you want the full picture on matching method to material, our guide to cleaning different upholstery fabrics walks through fiber by fiber.

Code WS (or SW): the flexible one

A WS code means the fabric can handle either water-based or solvent-based cleaning. This sounds like the easy code, and in a sense it is — it gives the cleaner room to choose the right tool for the job. Most modern sofas with synthetic blends fall here.

The catch is that “either method works” does not mean “any method, any strength, any amount of moisture.” A WS fabric can still water-stain if over-wet, and it can still be damaged by an aggressive solvent. The flexibility is for the cleaner to make a judgment call based on the soil and the fiber — light surface soil might call for a gentle water-based pass, while an oily, set-in stain might need a solvent spot treatment first. Having both options available is precisely why professional cleaning gets better results on WS fabric than a single-product home machine.

Code X: vacuum only — no liquids at all

An X is the warning label of the group. It means no cleaning agents of any kind — not water, not solvent. The only safe maintenance is vacuuming and light brushing. These are typically delicate decorative fabrics, certain woven textures, and pieces where any liquid will cause shrinking, bleeding, or distortion.

X does not mean your furniture can never be cleaned — it means it cannot be cleaned with consumer methods. A trained textile specialist can sometimes work on an X-coded piece using dry compounds or specialized low-moisture techniques after careful testing, but this is genuinely expert territory. If you have an X-coded heirloom or designer piece, the worst thing you can do is experiment. Vacuum it regularly, address spills by blotting (never rubbing) with a dry white cloth, and call a professional for anything beyond that.

Why the code is the start, not the whole story

Thirty-plus years and 60,000-plus jobs have taught us that two pieces of furniture with the same code can behave completely differently. Dye lots vary. A fabric that tested colorfast when new can bleed after a decade of sun. Previous owners may have spot-treated with the wrong product and set a stain you cannot see until moisture reactivates it. A pet’s accident may have soaked through to the deck regardless of what the face fabric is rated for.

This is why a code on a tag never replaces hands-on testing. Before any cleaning, we identify the fiber, confirm the code, and run a colorfastness and shrinkage test in a hidden area — a back corner, the underside of a cushion. Only then do we choose the method and the gentlest effective product. Our certified-organic, non-toxic solutions are hypoallergenic and safe around kids and pets, which matters when you are treating something the whole family sits on every day.

What this means for cleaning at home — and when to stop

You can safely do a fair amount of routine maintenance yourself regardless of code. Vacuum weekly with an upholstery attachment. Blot spills immediately with a dry white cloth, working from the outside in. Rotate and flip cushions so wear stays even. For deeper guidance on cadence, see how we explain how often upholstery should be cleaned, and for the broader picture our complete upholstery cleaning guide covers the full routine.

Where to stop is just as important as what to do. Stop before you use any liquid on an S or X code. Stop before you saturate a W or WS fabric. Stop before you rub a stain — rubbing distorts fibers and spreads the spill. And stop before you reach for an off-the-shelf cleaner on anything you care about; many contain optical brighteners and harsh surfactants that leave residue and attract soil faster. When the stain is set, the piece is delicate, or the code is missing, that is the moment for professional upholstery cleaning. Leather, incidentally, plays by entirely different rules — if that is what you have, read our take on leather versus fabric furniture care before doing anything.

If you are in Mercer County, NJ or Bucks County, PA and you are not sure what your furniture’s code means or how to clean it safely, we are glad to take a look. Homeowners around Princeton lean on us for honest, no-pressure advice — start with our Princeton upholstery cleaning page or call 609-586-5833 for a free quote. We will tell you straight whether it is a DIY job or one worth handing off.