Introduction: Growing Blue
The allure of indigo has always fascinated me. I've purchased blue powder and dyed yarns in the past, but always wanted to do some batik fabrics. This was the year. And to actually grow the plants that will produce the color blue. Blue is elusive in the plant world, a few flowers like forget-me-nots or hydrangeas are blue, but you can not extract a blue dye from them. There are several plants that contain the chemical indican from which you can produce a blue dye. They include woad, dyer's knotweed, Indigo tinctoria, and I. suifruticosa. I planted dyer's knotweed (polygonum tinctorium), as it was the easiest to obtain seed, and also to grow in my area of the Midwest.
Step 1: Planting and Growing
I ordered seeds from an indigo project undertaken by Rowland Ricketts at Indiana University. I started the seeds indoors under florescent lights as they require a long growing season. It has definitely been that, this year, but one never knows. (We still have not had a frost the middle of October.) Because of a late wet and cold spring I did not plant them into the ground until the beginning of June. They grew well in my organic plot at the community garden. I perhaps planted them too close together, but they produced more than I needed for my first year of experimentation.
Step 2: Harvesting the Plants
The information I read said to pick them in the August or September, when the leaves are starting to show a blue tint from crushing or insect damage. I cut a few plants and let them wither to see what would happen. Yep...starting to look blue!
Step 3: Direct Dye Processing
Now comes the tricky part. How to get that blue chemical out of the plants and useable as a dye that is light and wash fast. I chose the easiest method I could find. I just couldn't wait the months of fermentation and knowing it is a very smelly process I didn't want to run my husband off from the stench. What I did: I plucked the leaves and put them in a large pot. I added water to cover, and set it on an electric hot plate in the garage. I turned it to medium heat, as you want it to heat slowly for about 2 hours, keeping the temperature below a simmer...about 190 degrees. After about 2 hours, I turned off the heat and let it sit in the pot to cool down. It took on a metallic sheen, which I knew was correct. Then I strained it into a couple gallon jars through an old tea towel. If you dipped the fabric or yarn right in this liquid, or even simmered it, as you generally do with other natural dyes, you would get a color, but it would not be blue. Most likely green or yellow. Strange but true! You have to "reduce" the dye bath, or take the oxygen out of it. I accomplished that by using Rit Color remover. It's cheap and easily available. One and one-half tablespoons for the gallon of dye, stirred in and left to settle.
Step 4: The First Dip
Because I had to go to work, and sleep, and eat, and all that good stuff, my dye bath cooled off in the garage for a couple days. For the best dying you need the bath warm. For that I set the jar in a bucket of hot water. It only took about a half hour to come up to temperature, about 90-100 degrees. After the deoxidization the liquid becomes yellow. I dipped the yarn into the bath and it comes out yellow. As the yarn hit the air, the oxidation started immediately to turn green and then blue.
Step 5: Now the Fun Begins...
With the test run of the yarn, it was time to try fabric dyeing. I used 100% muslin cotton fabric that I boiled for 2 hours to remove any chemicals or gums that are in the cotton to make it more receptive to dye. I tried a few things to create patterns. Wax resist and stitch resist were the most successful. For the wax I used soy wax. It comes out of the fabric easier, with hot water, melts at a low temperature, and is easy to find at a craft store. I used a few things to make patterns, a simple wire wound in a spring, a chicken wire piece of scrap I found in the garage, a tjanting tool, which is available from dye companies, like Jacquard, and a cookie cutter. I simply melted the wax in a small disposable tin baking pan and dipped the instrument into it, and then pressed it on the fabric. The tjanting tool is dipped in the wax to fill the reservoir and then you draw an image on the cloth.
Step 6: Stitching and Resisting
Another method to use in creating a pattern is stitch resist. I drew some lines on the fabric and stitched a running stitch following the lines. Then I pulled it tight to gather up the fabric, making parts of it resistant to the dye. When the fabric is complete with stitches or wax resist it is simply dipped in the dye bath, pulled out to oxidize, and voila!....blue decorated fabrics of your own making. After the first dip and oxidation you can dip again and again, each time letting the blue color come through before proceeding to the next dip. Each time will intensify the color.
Step 7: Start All Over Again
And now what? Well, save some seed and plant next year's crop for even more fun and beautiful indigo cloth. Let a few of the plants go to flower, and eventually seed. I've picked some to see if the seeds were evident. Yes, they are. I just hung them in bunches to dry and then rubbed the flowers to see seeds dropping out. I will keep these till next spring and start again.