Reading a fabric's rub count: Martindale, Wyzenbeek, and what 'heavy duty' means

Ask how tough an upholstery fabric is and someone will quote a number: a Martindale figure or a double-rub figure. Both measure abrasion resistance, how well a fabric survives being rubbed, but they come from different machines and do not convert cleanly into one another, which is where confusion starts.

Martindale is the European method, run to the ISO 12947 standard. A disc of fabric is rubbed against a standard abradant in a slow figure-eight motion, and the count is the number of cycles the fabric survives before it shows defined wear. General domestic upholstery sits in the low tens of thousands of Martindale cycles; fabric rated for heavy domestic or general contract use runs higher, and severe contract fabrics are rated well above that.

Wyzenbeek is the North American method, run to ASTM D4157, and it reports double rubs. A weighted piece of abradant is pulled back and forth across the fabric, and one back-and-forth pass is one double rub. General residential fabrics are often specified in the low thousands of double rubs, while heavy-duty contract fabrics are rated in the tens of thousands.

The trap is treating the two numbers as interchangeable, because they are not. A back-and-forth Wyzenbeek stroke and a rotary Martindale cycle abrade the cloth differently, and no reliable formula turns one into the other. A specification should name the test as well as the number, and a fabric tested by one method should be compared only against others tested the same way.

The number is also a floor, not the whole story. Abrasion resistance says nothing about whether a fabric will pill, fade in sunlight, or stain, and a very high rub count on a loosely woven cloth can still snag. Use the count to screen out fabrics that are plainly too light for a hard-working seat, then judge the shortlist on fiber, weave, and finish.