As part of the Contextile 2014 exhibition a workshop with the artist Guida Fonseca was held at the Instituto de Design de Guimarães. The workshop adressed topics such as fibre characteristics and the identification of dye plants, mordants and their role in dyeing, the preparation of material to dye, the preparation of baths for dyeing as well as the dyeing of fabrics and yarns.
The main utensils for dyeing are a pot for the dye bath and a stove plate to keep the bath warm.
The dyeing procedure can be summarised as follows:
- First the yarns and fabrics have to be cleaned from dirt and fat. A detergent would be too aggresive for the fibres and would result in rough wool. It is better to use a soap for removing the fat.
- Mordants are substances which are used to set dyes on textiles. The type of mordant affects the fastness of the dye and also influences the shade. Compared to cotton, wool is far more receptive toward mordants. There are different methods to mordant a substrate. In this workshop pre-mordanting was used, which means that the substrate was treated with the mordant before dyeing. In order to dye 100 g of wool we prepared a bath with 20 g potassium alum and 5 g potassium tartrate. The yarn thickness also influences the necessary amount of mordants. For thinner wool yarns less mordant is necessary whereas for thick ones more. The mordants were dissolved in a pot with warm water (about 40ºC).
- After cleaning the wool and cotton were wringed out and transferred to the mordant bath. The wool stayed for 1 h in the bath.
- The wool was removed from the mordant bath and transferred to a pot with warm water. The 'tea' (see dyeing with walnut leaves) was added and the wool stayed in the simmering bath until the desired colour was obtained.
- Thereafter, the wool was well rinsed and spinned. As it was a warm late September day with temperatures higher than 30º in the sun. The wool air-dried without problems and very quickly.
In the following photos are all dye plants shown which were used during this workshop and their corresponding colour hues. Onion skin is often used to colour eggshells at Easter. But it can be also used to dye wool and obtain bold shades of yellow and orange (dependent on the time in the dye bath).
Corn marigold is one of the loveliest wild plants with its brilliant golden-yellow flowers. It can be found close to cornfields from June to September.
Besides being used in sweet and savory dishes or as remedy, turmeric can be used as a dye. Although known that it is not very light fast, it is commonly used for saris or Buddhist monks' robes. The dye bath was prepared by pouring hot water over the turmeric powder and stirring it well. The depicted yarn is made of cotton. It can be seen that compared to a wool yarn it doesn't absorb the dye completely.
A dye bath with leaves of the fig tree results in a beige colour. By adding a bit of turmeric it turns into an ochre.
Dyeing with leaves starts with the preparation of a 'tea'. A dye bath for 50 g wool, needs the double amount of leaves (100 g). Fresh as well as dried leaves can be used. However, when using fresh leaves the double amount is necessary. In case of the walnut tree also the branches can be used. Hot water was poured over the dry material in a pot and the mixture has simmered (not boiled) for 1 h.
The dye bath with Lichen was prepared in a different way. The bottom of a pot was covered with lichen. Wool, which was treated with mordant beforehand, was added. Hereafter, the pot was filled with wool and lichen in an alternating manner until the top layer was lichen. Cold water was poured over the mixture and set aside for 1 h. Thereafter, the mixture was heated and simmered until the wool showed the desired hue. It has to be noted that dyeing with lichen only works for wool. Moreover, the lichen can be dried and reused.
Other well-known plants for dyeing are the henna tree or the rubia tinctorum. Just the use of warm or cold water (aguq quente/frio) influences the colouration when using henna. The dye baths made with the roots of the rubia tinctorum result in shades of red, from orange to blood red. However, it is also possible to use leaves of any tree, such as the fig tree (Figueira), the hazelnut tree (Aveleira), the olive tree (Oliveira), the Mediterranean buckthorn (Sanguinho) or the lemon tree (Limoeiro). Simply experimenting!
Another note: There are plants, e.g. the Acacia mimosa, that release toxic vapours when used in dye baths. Therefore, the room with the stove has to be well ventilated.