Introduction: Naturally Dyed Fabric Experiment
This came out of a discussion about projects that we are planning for a S.T.E.A.M. club we are starting next year at a local elementary school. If you have any ideas that you think would be helpful, please feel free to comment below.
Stains are bad but dyes are good. I had a grass stain on the knee of my jeans which sparked the discussion. We started talking about all the natural dyes that are available. We decided that a fabric dying session might be good for our program. We could also use the natural dyes for Easter eggs next spring. I remember my mother using natural dyes on yarn when I was a child and we always dyed eggs.
For the sake of scientific exploration, I started with a pile of cotton fabric cut into squares. My research showed that the dyes would work better if I used something called a mordant to pre-treat the fabric first. I soaked my fabric in warm salt water (1/2 cup table salt to 8 cups of warm water) for an hour. I then let it dry. There was some debate, according to my research, as to whether you should rinse the salt out. I chose not to rinse.
I cut the fabric into three inch squares. After the dye soak, I ironed each swatch to heat set the stain and dry the fabric. Then, I gently washed the squares--swished them around in warm soapy water to see how much of the color would stay in the fabric. For each photo, I have a plain (un-dyed) swatch first for comparison. Then the unwashed swatch. Last, I showed the washed swatch.
Step 1: Grass
Since this all started with my grass stained jeans, I thought it was fitting to try this first. I recommend using your own grass clippings if you are going to dye eggs. That way you can be sure that you know that there are no pesticides on the grass. I personally would not do this after fertilizing the lawn just because I don't know what it would do to the egg. For fabric, I don't think it would matter.
Take the fresh clippings and crush them--in a mortar and pestle, if you have one (mostly because it is fun but also to crush the cell walls and release the chlorophyll). Mix with water and add the fabric. I let it soak for a hour--to give it a chance to totally absorb.
There are other green things you can try--if you don't have any grass clippings. I know spinach makes a nice green but you can also try kale, tree leaves, or a variety of herbs.
You could try other liquids besides water--rubbing alcohol might work well. I am planning to work with young children and am concerned about keeping everything kid friendly, easily accessible for when they go home and want to experiment more, and I want to keep the hot items to a minimum.
This turned out to produce a pale yellow green. I expected it to be darker. The egg had to soak for quite a while and even then it dyed a tan shade of green--sounds weird but that is the only way I can describe the color.
Step 2: Onion Skins
This is one that my mother did with us as kids every year at Easter time. The dry outer layers of an onion make a pretty brown dyed egg.
For this project, I boiled the skins of 5 onions in 2 cups of water for 15 minutes. I dropped an egg in for the last 4 minutes. I soaked one square of fabric in the hot liquid for 10 minutes. After the liquid had cooled, I soaked a fabric square for 10 minutes. I knew that this dye worked when hot but I wanted to make sure that it worked cold too--I do not know if we will have access to a stove during our after school STEAM club. I also like the idea that no one will get burnt.
The photos show the swatch soaked in hot onion skin broth and cold broth. The egg picture shows an un-dyed egg, the 4 minute egg (I got hungry waiting for things to cool so I ate my soft boiled egg), and an egg placed in cooled broth for only a minute (my assumed attention span of a child).
A little bit of color showed up in my wash water but not so much that you could tell a difference in the fabric.
Conclusion: onion skins make a good natural dye.
Step 3: Beets
For this one, I tried to find beets in the produce section of the grocery store but they were out. I ended up with a can of beets.
I tried soaking the fabric in the best juice straight out of the can. I heated up the beets and the juice and soaked a new piece of fabric. I wanted to see if the hot liquid dyed a darker color.
I did not find a noticeable difference between the hot and room temperature versions. This means that I don't have to risk the kids getting burnt fingers. I can put a teenager in charge of this station when we are working with the kids. I was not impressed by the dye color.
Step 4: Turmeric
This is a first time thing for me. I recently bought turmeric in order to try turmeric milk (an instructable that I read) and thought it might make a nice yellow dye.
I mixed a tablespoon of turmeric with water and soaked my piece of fabric for about 10 minutes. After seeing how well this worked, I may be taking my white cotton crochet dress and changing it to a yellow cotton crochet dress. I just love this color! Washing resulted in yellow water but the fabric still retained the bright color.
I expected the turmeric egg to be more yellow. This slight orange color was a little disappointing.
Conclusion: nice dye for cotton fabric; not so good on eggs.
Step 5: Coffee/Tea
Herbal teas do not work so well as dyes but you can still run a decent experiment by letting the kids try it if they want to.
I recommend strong black tea or coffee--so that you get the most effect. I only had some instant coffee in the cupboard. I made it pretty strong. After a nice long soak, there was not much color. I tried it cold too. Again, not much color staining the fabric.
I used 2 tea bags and just under a cup of water. The results were a little better than the coffee, but not by much.
Just to try something different, I sprinkled wet tea leaves directly on the white fabric. I was hoping for speckled effect. Even ironing directly on the tea leaves did not enhance the effect. I got blotchy light tan spots on the white fabric. So disappointing.
Washing did not remove much of the color. I did expect the coffee to stain darker than the tea. This was not the case. The hot coffee was only a tiny bit darker than the cold.
The tea dyed egg was slightly brown.
Conclusion: if you just want to take the 'stark white' out of an outfit, coffee or tea might be a reasonable thing to try. The result is so mild that the outfit will still look pretty white. Maybe a different kind of coffee would give a more dramatic results.
Step 6: Dirt
We did this one for the first time while we were on vacation years ago. We were staying in Georgia but we were in Alabama for the day. We were at a science museum gift shop. They had t-shirts that were dyed with genuine Alabama dirt.
On the way back to the condo, we stopped at the store and bought plain white t-shirts. I gave the boys spoons from the kitchen and the bathroom trash can. They dug up some Georgia red dirt and then we added water. They each added their t-shirt to the mud mix. It is a good idea to do this in the empty bath tub. They mixed for a while. I hosed down the mess that was totally contained in the bathtub--wasn't I clever? The next day, we rinsed off the mud and heat set the stain by throwing them in a hot drier. After the shirts were washed, they were a beautiful shade of terra cotta.
I live in Michigan. Michigan dirt is not as pretty as southern red dirt. A Michigan dirt shirt is gray. Yes, we made one to compare to the Georgia shirts. When we do this with the STEAM club, we will be using Michigan dirt. If I find a family member or close friend that is going south any time soon, I will be asking them to bring me back a Ziploc full of the pretty red dirt. (I would not ask a casual acquaintance to do this--they don't need to know just how strange I can be.)
I mixed a cup of dirt with water. I soaked the fabric. I had to rinse the mud off before heat setting. This time the fabric stayed white--maybe potting soil is not the same thing as dirt. I have to try again with dirt from the yard.. Maybe if I find a spot with some clay in it.
Step 7: Any More Ideas????
I plan to try pomegranate this fall (not available at this time of year) and grapes when mine come ripe. Blackberries will come ripe in a while.
I am willing to add to this list of natural dyes. Does anyone have any suggestions?
I put all my samples into book form--partially so I could save my project, but also to use in our STEAM club. I will make an experiment journal for each of the kids. They can record their procedures, results, and ideas for other colors or how to set the stains better. We hope this will help connect the science of exploration to the necessity of communication in written form. Keeping a good scientific journal involves attention to detail and good writing skills.