Natural dyes for dyeing cotton yarns

[richardandtracy]

Yarn dyeing with natural dyes is superior dyeing yarn with chemical dyes. The Yarns dyed using natural methods are much more resistant to light and heat. In nature, there are millions of sources of natural dyes. ...

I have to take issue with you a bit on the first two sentences.
One of the reasons we use so many chemical based dyes these days is because they are superior to plant based dyes in a number of ways. These include:

1. Colour Fastness during washing
2. Light fastness
3. Range of colours
4. Brilliance of colour
5. Consistency & repeatability between batches
6. Colour density
7. Quantity of active colourant required is much less

There are a few cases where plant dyes are superior to chemical dyes in terms of colour fastness during washing & light fastness, but I cannot agree that these few justify the blanket claim that 'The Yarns dyed using natural methods are much more resistant to light and heat', because in more cases than not, the reverse is true. The reason why life & clothes are more colourful now than they were 200 years ago is because of the move away from plant dyes to synthetic dyes. The range & durability of the colourants is hugely improved, as have the amount of the earth's resources required to produce the colour. The Imperial purple used by the Romans required may thousands of sea creatures to be harvested, killed and their tiny dye sacs removed for each square metre of fabric - amounting to tons of waste per square metre dyed. The modern equivalent dye 'Mauve' is a completely synthetic, and not one creature dies to produce it.

I do agree that there are a large number of plant dyes, and many have very subtle colours, many being less harsh than chemical dyes, and sometimes being much more attractive. So, in some specialist situations, used by very knowledgeable people, plant dyes give an amazing and beautiful result. However, the reason why the global textile industry uses mostly synthetic dyes is founded on the fact they offer considerable advantages in terms of cost, durability and use of natural resources compared to plant dyes.

I will now take my professional engineer's hat off.

Regards,

Richard.