Bolton Consultancy Ltd

Colour Fastness

Fastness Test Methods

As of 2009, there are over 100 different test methods to cover the many aspects of colour fastness, and these are published as BS EN ISO 105. A large proportion are provided for the dyer to identify potential problems during production.

The key methods which are directly relevant for consumer satisfaction are:

Bolton Consultancy Ltd has many years experience providing training in and assessing competence in fastness testing and currently is an approved trainer for the SDC Training.

Questions on Fastness Test Methods

Here are some of the questions that are frequently asked by training delegates:

Why does ISO 105 C06 have 32 different variations and C09 2 different detergents?

ISO standards are expected to be international and inclusive worldwide.   Standards relating to clothing have to accommodate different consumer habits.   Clothing laundry is surprisingly complex, with habits being both personal and culturally diverse.   In the UK most homes have an automatic washing machine of a similar style, and our detergents have been developed to give a good level of stain removal together with a level of cleaning to meet UK consumer expectations of cleanliness and hygiene.   In other countries hand washing or washing in cold water is more common and detergents are formulated accordingly.

Why test for perspiration and doesn't it smell?

All adults perspire and this can result in shade change of the dye or lead to staining of other clothes in wear.   The synthetic perspiration solution is used fresh and does not include the bacteria which produce the odour; hence doesn't smell.

The standard methods don't assess staining on to silk, hair or skin.   Isn't this a problem?

The standard methods do use a multi fibre adjacent fabric which includes six of the main chemical types.   Silk, wool and hair are all protein, which is chemically similar to wool.   Nylon is also stained by the same kinds of dyes.   Monitoring the staining of wool and nylon during testing provides adequate assessment for most consumer requirements.

Tests don't replicate consumer practise, how can they be relevant?

National and international standards committees draw membership from dye makers, dyers, garment makers, retailers and consumer groups.   Based on years of experience, the standard methods provide simple uniform techniques which enable sorting of good and poor dye lots to enable selection for consumer satisfaction.  

There are standard methods, but no published performance requirements.   Why not?

The methods are standardised to enable dyers and dye makers to produce dyes and dyed fabrics for all their customers using one set of quality control tests.   Different retailers and brands set different requirements depending upon the requirements of their consumers (final end user), how the garment is to be worn or used, the expected durability of the garment and the recommend cleansing instructions.   In the UK most retailers and brands publish their own set of product performance criteria for their suppliers: this is their product difference, so these are usually kept confidential.