Every t shirt will have been made to a specification to determine how it responds to its use in daily life. The question is what does a t shirt have to put up with in daily life? It will be rubbed as you run in it, it will be washed, your sweat will be put on to it and of course being a t shirt it will be exposed to the sun.
How is the fabric checked to make sure it is suitable for life as a t shirt? It undergoes standard test methods which replicate an average type of rubbing, washing, perspiration and sun exposure to give the dyer and the retailer an idea that it will be suitable.
These tests are internationally accepted and approved through an organisation called ISO and in the UK this is organised for British Standards Institute BSI through the Society of Dyers and Colourists (SDC).
To test the dyed and finished t-shirt for its wash fastness a sample of the fabric is taken and sewn together with a piece of fabric called a multifibre strip. This fabric is specially engineered and specified in the standard to always be the same. It contains the following fibres Wool, Acrylic, Polyester, Nylon6.6, cotton and acetate.
These 2 pieces of fabric are placed in a specially designed machine with a standard detergent, with a very specific amount of liquor to goods ratio and then these are washed at whatever temperature you feel the garment should be washed at domestically.
If any dye is removed by the detergent and action of the machine from the dyed fabric it can either stay in the liquor or it might stain the fibres on the multifibre strip. The amount of loss of colour from the fabric and the amount of staining on the multifibre is assessed against the original fabric and against an untested multifibre strip using greyscales. If the staining is below the manufacturers specified level as is the loss of colour then the fabric can be used for the end purpose.
Each new colour will be tested to ensure compliance with various test methods to ensure the product is suitable for end use.
So remember the fact that your t shirt lasts as long as it does is because of the technical testing that is done which supports the environment and sustainability. Without these standard test methods there would be no way of measuring the quality of the garment produced.
The Life Story of your T-shirt
This blog was written as part of an online event run by The Institute for Social Marketing as part of the Festival of Social Science week (7th-14th November 2015).