Unravelling textile testing | Colourfastness

Colourfastness measures a textile’s ability to resist or withstand fading. Fading typically refers to a change in the hue, depth, or brightness of a colour.

We perform a range of colourfastness tests when developing a new textile, testing its resistance to fading in UV light as well as laundering and rubbing.

Colourfastness to laundering measures a fabric’s ability to withstand fading or colour loss during washing and/or dry-cleaning.

The test replicates specific cleaning methods, measuring any colour loss against a set of five grey scales. A result is awarded on a scale 1-5, with 1 being least colourfast and 5 being most colourfast. In this instance, a result of 4-5 is what we strive for.

Most of our washable textiles are rated for delicate or gentle washing (i.e. a delicate setting) with a delicate washing liquid. Therefore, we always approach spot cleaning with water or a solution cautiously, as it tends to be more localised and aggressive.

If spot cleaning is necessary, always use a clean dry white cloth first to reduce any colour loss. This can often remove a stain.

Colourfastness to rubbing (known as ‘crocking’) measures a fabric’s resistance to colour loss when subjected to rubbing or friction from another fabric.

This is particularly relevant for upholstery textiles – you’d want to be confident when you stand up from sitting on dark coloured sofa that your white trousers haven’t changed colour.

To test, a white cloth is used as a standard abradant and rubbed against the test fabric in both wet and dry conditions, with wet being more severe. Any colour transferred onto the white cloth or lost from the test fabric is analysed and measured against a set of 5 grey scales, with 1 being least colourfast and 5 being most colourfast. This result helps us to determine the recommended usage for an upholstery fabric.

Colourfastness to light measures a fabric’s resistance to colour loss when exposed to UV light.

The test swatch is placed under an artificial lamp in controlled conditions to replicate the effects of natural light exposure. To establish the degree of colour change, the fabric is removed at specific intervals (usually 40 hours for interior furnishing fabrics) and compared to both a swatch of the original fabric and a standard set of ‘blue scales’, which are also subjected to the test conditions.

The blue scale is a testing card of eight standard blue wool swatches.

A rating from 0-8 is awarded by identifying which of the strips has faded to the same extent as our test sample. The test result is published in our product specifications.

1 indicates almost complete colour loss (you’d never see this result on our fabrics) and an 8 is the unicorn result – it doesn’t exist! Generally, a result of 5 or greater is optimal for drapery fabrics and 4-5 or greater is considered sufficient for upholstery fabrics. A result of 7 is an extremely high result.

With that be being said, many variables can affect a textile’s performance. These include the composition, the dye method (solution dyed, piece dyed, yarn dyed, or digitally printed), quality of the dyestuff, and finishing processes.

Ecofast™ pigment inks are not only more environmentally friendly than conventional inks, they also provide superior colourfastness to light, achieving exceptional results of 6-7 on the blue scale test.

Due to the hole in the ozone layer, we have extremely harsh environmental conditions in Australia and New Zealand, especially regarding the amount of damaging UV light.

Our lifestyle and mild weather call for transitional architecture favouring indoor-outdoor living and expansive glass windows. Therefore, even textiles that are technically indoors but on the periphery of the home are subject to extremely high levels of UV light.

Everything fades! Including the bricks and paint on your house, your timber floors, and your youth! As mentioned above, the dye method and quality are critical but in general, synthetic or man-made fibres tend to outperform natural fibres in fade resistance.

The fibre most resilient to UV damage is acrylic, very closely followed by polyester. Of natural fibres, cotton and linen have quite good sun resistance with quality dye stuff, much more than silk for example. However, the best fibre type for high-sun environments is solution dyed acrylic, olefin, or polyolefin.

Learn more about protecting your home from damaging UV rays.

One of the most effective ways to reduce UV damage is to install a quality curtain lining.

The leading edges of a curtain (those facing the windows) are the most exposed and therefore most vulnerable to sunlight degradation. A trick to either hide fading or to slow down the onset of fading is to rotate your curtains – moving the leading edge to sit against the wall and vice versa.

UV damage results from both from direct and indirect light, as it bounces off surfaces within your home. In addition to regular vacuuming, rotating the furniture within a room and rotating individual cushions will minimise the appearance of fading, making it appear more gradual and even to the eye.

Although test results provide a guide, there are many other factors that can contribute to a fabric’s performance – i.e. the surrounding environment, proximity to the window, direction the house is facing, children or pets, the clients’ expectations for the level of care and maintenance required, and whether the inherent characteristics of the textile are in line with these expectations.

Just as you would take extra care of a silk shirt or a woollen jersey, extra care is also necessary for your interior soft furnishings. Don’t install and ignore!

Learn more about looking after your upholstery textiles.