Natural dyes are dyes or colorants that are derived from plants, invertebrates or minerals. The dyes that my partner and I made were from vegetables and fruits. Our first dye was a deep pink color from simmering raspberry in water and our second one was an orange-brown from the turnip. Thus, we used a berry and a root of the plant which gave us a variety.
We started our work by scouring the wool, which was washing the wool to remove the lanolin. Then we mordanted the wool by dissolving 1tsp of alum in it and letting it simmer for 20 mins. The mordant is the chemical link that fixes the dye to a substrate by combining with the dye pigment to form an insoluble compound. Here the mordant is the alum!
Our first dye bath was the raspberry one. This was divided into three pans. One was just the pure raspberry bath, one had the raspberry bath with iron and the third one was raspberry with tartaric acid. Each was heated at a temp of 140 degrees Fahrenheit and the mordanted wool and muslin cloth was added into it to absorb the color.
Looking at these dye baths, the colors I interpreted were something like these:
|
DYE |
Wool |
Muslin |
|
Pure Raspberry |
Light pink |
Light Red |
|
Raspberry+ Tartaric Acid |
Orange |
Orange |
|
Raspberry + Iron |
Brown |
Purple-Red |
However, the colors were quite different from my assumptions. This is because wool and the muslin doesn’t soak the dye completely.These were the actual colors we got:
|
DYE |
Wool |
Muslin |
|
Pure Raspberry |
Grey Brown |
Light Brown |
|
Raspberry+ Tartaric Acid |
Peach |
Peach |
|
Raspberry + Iron |
Red-Brown |
Purple-Red |
The muslin cloth has cotton fiber, which retains 24 to 27 times its weight in water, breathes by absorbing and releasing moisture quickly. This absorbent quality makes cotton an easy fabric to dye. Wool absorbs up to 30 percent of its weight in water and is the most absorbent of all fabrics.Wool is one of the best fabrics to dye as the color will penetrate the core of the fabric and permanently bond with the fibers. The colors are clearly visible in the muslin cloth because it was cleaner than the wool. The wool could have been mordanted ed easily so that it could take the color better.
Using the pH strips we found that the Raspberry dye with the tartaric acid was the most acidic with the lowest pH followed by the dye with iron and then the pure dye. All these were under the ‘Very acidic’ bar.
|
DYE |
pH |
|
Pure Raspberry |
5.75 |
|
Raspberry+ Tartaric Acid |
5.5 |
|
Raspberry + Iron |
5.0 |
The second part of the experiment was to make another dye bath and use the Shibori technique of dying.The second dye bath was made from Pink turnips. Shibori is a Chinese technique of dyeing where the cloth is folded in different ways and tied with rubber bands and simmered in the dye bath. When opened, various different patterns are created using the dyed and blank space.
A pinkish peach color was seen on the muslin cloth and the wool. The pH was more than that of the raspberry dyes. It was 6.25 and so it was less acidic than any of the pH dyes.
A few other dyes that we tried were turmeric and cochenille dye.
Since all these dyes had acidic properties, it wasn’t safe to drown them just like in the drain. Especially when they contained tartaric acid and iron which are harmful substances and pollute the water. Therefore to neutralize these dye solutions a base had to be added so that they were safe to be drowned. We used vinegar to neutralize these solutions. Along with this, the water has picked up dirt from the wool and soap. Once this water is gone down the sink, the sanitary sewer pipe in the streets carries it wastewater water treatment plant where it is processed and treated and all the wastes are removed, bringing the water back to a neutral pH 7 and released back to the environment as groundwater or surface water.
