How to Read a Fabric Spec Sheet: Composition, Weave, Rub Count, and Finish

The short answer: a spec sheet is a set of test results, and each line answers one question

You have the maker's fabric page open on one screen and a photograph of the sofa on the other. You have paid for luxury upholstery that pilled, stretched, or shone at the arm long before it should have, so this time you read the sheet first. It gives you a composition line, a weave name, a six-figure abrasion number, and a finish line. None of the four, on its own, tells you how this cloth will hold up.

A spec sheet is a set of laboratory test results, not a description. Each line answers one narrow question, with a named method and a unit behind it. The line the mill did not print tells you more than any line it did. That is how to read a fabric spec sheet: a stack of separate test results, never a single verdict.

A residential buyer needs four of those lines: composition, construction, abrasion, and finish. The certification line and the flammability line come last, as scope statements. They name who tested what, and say nothing about daily wear. A sheet carrying an abrasion number and no composition line was written to be skimmed.

This page reads the document in front of you. It does not teach how a linen blend behaves against a wool blend, or how a tight weave differs from a soft-textured one; how to choose a sofa color and fabric that lasts owns that. It does not put your hands on the square; how to evaluate a fabric swatch with eight bench tests owns that.

The composition line: fibre by percent, in the order that decides the wear

Fibre content is stated by percent, and the fibres are listed in descending share. The first fibre named decides how the cloth wears and how it holds a crease over years of use.

A blend line naming a fibre family with no percent attached, something like "cotton/poly blend" and nothing after it, did not come off a mill's test report.

This is also the only line you can check against the swatch in your hand. A fibre blend has a hand and a way of catching light. If the square does not match what the composition line describes, ask before you order.

Keep the reading simple here. Percent, in order, checked against the physical sample. What each fibre then does to a finished cloth belongs to another page.

The construction line: weave name, weight, and width, and why the weight does the work

The weave or knit name tells you how the yarns cross: plain, twill, satin, jacquard, dobby, bouclé, chenille, velvet, knit. Worth knowing as vocabulary. The name alone says almost nothing about how the cloth will perform.

The weight does that work. Upholstery fabric weight, given in ounces per linear yard or grams per square metre, tells you how much yarn is actually in the cloth. The width, given in inches, decides yardage, and has no bearing on durability at all.

Two cloths can carry the identical weave name at very different weights, and in every way that matters to wear, they are different fabrics. A sheet that gives you a weave name and no weight is describing a look. The cloth itself is still unaccounted for. If the weight is missing, that is the question to ask before the weave name means anything.

The abrasion line: double rubs, cycles, and what a high number does not promise

This is the line every residential listing prints, and the one worth reading most carefully, because it does less work than it appears to.

Abrasion is measured by two methods, on two machines, in units that do not convert. Wyzenbeek, ASTM D4157, clamps a specimen and abrades it back and forth against a cotton duck or wire-screen abradant, reporting in double rubs. Martindale, ASTM D4966, rubs a circular Lissajous motion against a wool abradant, reporting in cycles.

On a residential listing the comparison gets stated as Wyzenbeek versus Martindale, as though the two were rival brands and not two lab setups reporting in different units. A figure with no method beside it is a figure with no meaning. A double-rub count does not compare to a cycle count any more than miles compare to litres.

The Association for Contract Textiles, ACT, publishes voluntary performance guidelines for these tests. For woven and knit upholstery, the low-traffic guideline is 15,000 double rubs Wyzenbeek or 20,000 cycles Martindale. The high-traffic guideline is 30,000 double rubs Wyzenbeek or 40,000 cycles Martindale. Those guidelines were written for contract interiors, offices and hospitality. A residential sofa is judged against the low-traffic line.

ACT is also explicit about what the numbers do not tell you. Both methods, in its own words, "measure flat abrasion resistance and do not consider edge abrasion or other types of surface wear." ACT states that "higher abrasion numbers do not necessarily indicate a significant extension of the fabric's service life," and that "test results exceeding the ACT high-traffic abrasion guideline have not been shown to be an indicator of increased fabric lifespan." Most directly: "a fabric with twice the number of abrasion cycles does not indicate double the service life."

Put plainly. Below the guideline, the abrasion line rules a fabric out, and that is a real decision you can make on the number alone. Above it, the line cannot rank two cloths that both clear the threshold. A six-figure double rub count on a residential sofa listing, with no method beside it, is a marketing number wearing a lab coat. If the industry's own reference body will not let that number promise a longer-lived cloth, a product bullet should not either.

The lines that do the comparing come next.

The lines most sheets leave out: pilling, lightfastness, crocking, seam slippage

Four more properties get tested and graded on a real spec sheet, and most residential listings skip all four.

Pilling is tested to ASTM D3511, brush pill, or ASTM D4970, Martindale pill, graded on a five-class scale where Class 5 means no pilling. The ACT minimum is Class 3.

Colourfastness to light on upholstery is tested to AATCC TM16, on a five-class scale after a stated exposure period. The ACT minimum is Class 4 at 40 hours.

The crocking test, meaning dye transfer under rubbing, runs to AATCC TM8, dry and wet, on a five-class scale. The ACT minimums are Class 4 dry and Class 3 wet.

Seam slippage is tested to ASTM D4034, a pull test reported in pounds of force. The ACT minimum is 25 pounds.

One more line. The cleaning code, a single letter, W, S, WS, or X, on most upholstery tags, is a cleaning instruction and not a durability grade. This page will not decode the letters; how to clean a fabric sofa without harsh chemicals covers the routine.

An absent line is not automatically a failure. A small mill tests to the specification its customer buys, and a residential-only cloth may never have run a pilling or crocking test. Treat a blank field as a question, and send it to the maker in writing.

The finish line and the certification line, read on a real sheet

The finish line names the chemistry applied after weaving, and the honest version names what it excludes and scopes it to the fabric layer. The certification line names a standard and its holder, which makes it a statement about that textile. It does not reach the assembled sofa. The flammability line names a standard and a compliance path.

Here is a real one, read the way this page has been asking. Covelle's fabric line states, verbatim:

"Sourced from Dorell Fabrics, a supplier that holds OEKO-TEX Standard 100 across its product line. PFC-free finish. No chemical flame retardants. No added formaldehyde."

Read it back against the rules above. The certification is named, OEKO-TEX Standard 100, and its holder is named: Dorell Fabrics, at the supplier level, never Covelle. OEKO-TEX Standard 100 certifies individual textile products and their components against a harmful-substance limit list, every thread, button and accessory tested. It is a supplier-level textile certification, not a whole-assembled-product emissions test. What OEKO-TEX Standard 100 covers on upholstery fabric walks through the standard's scope and product classes in full. The finish chemistry is named by what it excludes, scoped to the fabric layer. The flame-retardant sentence names what is absent from the cloth, which is a statement you can check, where a weaker sheet hands you a category label. The flammability standard for the assembled piece belongs on the sofa's own sheet, not on the fabric line.

Covelle's own standard for this kind of disclosure reads: "Every material documented. Every active certification verifiable through its issuing body." That standard, and the layer-by-layer disclosure behind it, sits on the Transparency page.

Now the part that makes the instruction fair to give. That sentence is the certification line, the finish line and the flame-retardant line. It is not the composition line, the weight or the abrasion result. Those are the lines to ask any maker for in writing, and that includes this one.

The sheet, read in order: six questions to send before you order a swatch

Before you order a swatch, write down six questions and send them to the maker.

What is the fibre content, by percent? What is the weave name, and what is the fabric weight? What is the abrasion result, and by which method, Wyzenbeek or Martindale? What are the pilling, lightfastness and crocking grades? What is the finish chemistry, and what is it free of? Who holds the certificate printed on the sheet?

A maker who answers all six in writing has given you a spec sheet. A maker who answers with a photograph has given you a mood board.