Colour Fastness to Washing, Rubbing and Light: The Test Report Sofa Cover Importers Should Request
An online seller in Germany launched a corn Velvet Slipcover range in twelve colours in March. By the third week the reviews had turned: the navy cover marked a white shirt, and the wine shade bled onto the light piping. Nobody had asked for a fastness report. The mill said the fabric was "tested" — for what, at what grade, on which colour, no document said. The listing was pulled and 1,400 units went to a liquidator.
The Four Fastness Tests and What Each One Measures
Four ISO 105 methods cover nearly every complaint you will receive. ISO 105-C06 covers domestic and commercial laundering: the specimen is washed against a multi-fibre adjacent cloth with steel balls at a stated temperature. ISO 105-X12 covers rubbing, usually called crocking, run dry and wet with cotton cloth under a nine newton finger. ISO 105-B02 covers light under a xenon arc, and E04 and E01 cover perspiration and water.
Each test returns two separate numbers, and importers read only one: the shade change and the adjacent staining. A cover can hold its colour at grade 4 while staining the multi-fibre strip at 2. The staining figure is what produces the review about the white shirt, so specify both.
The Grey Scale: What a 3 Costs You Against a 4
Washing, rubbing and perspiration are graded on the 1 to 5 grey scale, where 5 means no visible change. Each step roughly doubles the visible difference. A grade 3 is visible across a room; a grade 4 needs looking for. Working minimums: 4 for colour change and 3-4 for staining, dry rub 4 and wet rub 3-4.
Light is graded separately, on the 1 to 8 blue wool scale, and 4 is the practical floor for a sunny room. Anything lower fades unevenly, and uneven fade looks worse, because seams and folds hold their shade. A corn velvet slipcover for living room seating is the classic case: the pile direction changes the reading, so the report must state how the sample was rubbed and exposed.
Dark Shades, Dye Class and Fibre-Specific Risk
Dark shades fail first and fail most often. A navy or wine cover carries several times the dye load of beige, and the surplus sits on the fibre as unfixed dye. Specify dark shades one grade higher than lights, and require reduction clearing after dyeing; skipping that step is the usual cause of a 2-3 wet rub result.
The mechanism differs by fibre. Polyester in disperse dyes loses colour to sublimation and thermomigration, which heat setting accelerates. Cotton in reactive dyes loses it through hydrolysis of unfixed dye. Construction matters as much as dye class: a printed sofa cover for one, two and three seater sofas carries pigment on the cloth surface and rubs worse than a yarn-dyed or jacquard build where the colour sits inside the yarn.
Wash Cycles and Temperature: Test to the Care Label
Test to what you print, then add margin. If you sell a cover as machine washable at 30 °C, request five cycles at 40 °C, because the first cycle is not the worst one and the customer's machine runs hot. ISO 105-C06 defines each condition by temperature, time, liquor ratio, alkali and abrasive load, and the report must state the condition code it ran.
An all season sofa cover for daily furniture protection is washed far more often than a decorative throw, so five cycles is the minimum and ten is defensible. Add bleach tolerance where the label permits it, and test the elastic, piping and thread with the panel, since a trim that bleeds ruins the panel.
Why the Report Must Name the Colourway, Not the Range
A report issued for a range or a fabric quality is nearly worthless. Fastness belongs to a dye recipe on a cloth at a shade depth, so a beige certificate says nothing about navy. Require the report to name the colourway reference, construction and dye lot. Where a mill offers one report across ten shades, treat it as no report.
That is why a multi colour stretch sofa cover sold across many shades is a paperwork problem before it is a quality one. A jacquard or yarn-dyed build lowers the risk because colour is fixed before weaving, but you still need one report per colourway per season. Build that into the unit price.
Laboratory Choice, Report Fields and the Clause to Write
Use a third party ISO 17025 laboratory — SGS, Intertek, TUV or Bureau Veritas — not the mill's in-house sheet. In-house data helps process control between lots, nothing in a dispute. Check for the method code, sample description, dye lot, date and stamp, and ask for staining grades listed fibre by fibre rather than averaged.
Then put it in the contract, because a request in an email is not a specification.
- Methods required: ISO 105-C06, X12 dry and wet, B02 and E04, with condition codes.
- Minimum grades: colour change 4, staining 3-4, dry rub 4, wet rub 3-4, light 4.
- Cycles and temperature: five cycles at the care label temperature plus 10 °C.
- Scope: one report per colourway, per construction, per dye lot, per season.
- Trims: elastic, piping, thread and labels tested with the panel.
The Bottom Line
A fastness failure arrives as a return with a defect code, not as a complaint you can negotiate. Name the methods, grades, cycle count and colourway on the purchase order, and accept only accredited reports that carry a dye lot. A mill offering one certificate for twelve shades has already answered you: the testing was never done, and the cost of that lands on you.