Natural Dyeing

It's been two years that I've been contemplating, researching, and looking forward to my inevitable first (real) natural dyeing experiment. In fact, I had a stash of onion skins sitting in my cupboard for about a year now. It was when I was WWOOFing in Canada that I was exposed to dye plants and how you can use them to produce natural and even sometimes rich colors of yellow, purple, green, brown, beige and red. I even attended a fair with my host family where we gave an indigo dye demonstration! So, ever the procrastinator (it's not laziness!), I waited for two years until I was presented an opportunity in a college Chemistry course to create my own lab project. My natural dye experiment was born!

You may be wondering how naturally dyeing fabric with plants, roots, berries, and even bugs relates to Chemistry at all. Well, I'm glad you asked. In order for the color to 'bite' to the fabric you usually need to add something to the mix to make it stick. In the distant past, urine was sometimes used. Being the civilized society we are today, we have a better way. So, metallic salts were found to partly attach to the fibers and partly to the dye so it wouldn't wash out right away. These are called mordants and the most common ones are alum (potassium aluminum sulphate) and iron (ferrous sulphate). Some of the other ones, like chrome, can be much more poisonous and their use is discouraged. In my project, we used red and yellow onion skins, blueberries, and black tea along with mordants of alum, iron, and copper.

When dyeing naturally you can only use natural fibers so in our experiment we used cotton and linen fabric so we could compare the results. Below are the results of all three dyes. Each had a different mordant and the darkest color was obtained with using the iron mordant.  My favorite result is the dark army green that was created using the onion skins and iron mordant.  

Dyeing with Tea

Red and Yellow Onion Skins

Blueberries- yum!

Even after washing, the colors held up well except the blueberry which lost it's lovely purple color. Overall, natural dyeing is a science with many variables and it is hard to get the same color twice. Factors such as amount used, temperature, pH, length of time, and even growing conditions of the plant effect the color. The good news is, every time is a surprise!