Dyeing of textiles
Practical Action
Processing of the plant can take one of many forms, but usually takes the form of soaking
or boiling the plant to extract the dye. Some plants, such as indigo, need special
preparation for use. Some plants will need boiling to extract their dye while others can
merely be soaked for extended periods. Detailed instructions for processing of a wide variety
of plants can be found in some of the texts given in the reference chapter at the end of this
document.
The process of dyeing
Application of the Dye
Dyeing can be carried out at any of the following stages in the textile manufacturing stage:
The fibres can be dyed before they are spun. Fibre dyeing provides a deep penetration
of the dye into the fibre, giving even colour and excellent colour-fastness.
The yarn can be dyed after spinning but before the product is woven or otherwise
fabricated. This is called package dyeing.
Before the fabric is finished, it can be dyed in lengths (piece dyeing).This process
allows manufacturers the opportunity to produce fabrics in their natural colours, and
then dye them to order.
In cross-dyeing, fabrics of two or more fibres can be dyed so that each fibre accepts a
different dyestuff and becomes a different colour, through the use of appropriate
dyestuffs for each fibre.
It is essential for the correct identification of the fibre or other fabric to be made before
dyeing commences.
Methods of dyeing
There are a number of methods of applying dye to a fabric. Although the most common
method used for applying natural dyes is the vat method, there are techniques which have
been developed to allow patterns to be incorporated during the dying process. It is worth
bearing in mind that using natural dyes is
a complex art and the skills required for
using natural dyes are learned over many
years. Don’t be put off if you don’t get the
desired results at the first attempt!
Vat Dyeing
In the simplest form of dyeing a textile
material is immersed in dye and gradually
brought to the boil. Alternatively the fibre
is allowed to sit and soak for several hours
or days. During this period, agitation is
necessary to allow full penetration of the
textile by the dyestuff. Depending on the
type of fabric and dyestuff used, certain
salts or acids may be added to assist
absorption of the dye.
7