Indigo and the Celts
For me, learning about my heritage is one of the coolest and most fascinating things I can spend my time on. As someone with Celtic roots, I love to hear stories about brave warriors covered in their blue markings. These blue tattoos were war paint, created from the woad plant. Just as the woad plant can dye skin, it can also dye fibers. Woad is the original source of indigo, the beloved (and at one point only source) of blue pigment for dyeing fibers.
To make indigo from woad, Ancients Britons would pick the leaves and grind them in a mill. They would then ball up the leaves, placing these balls into drying sheds for weeks until they were as hard as wood. At this point, they were broken apart, covered in a tiny bit of water (or, as some accounts say, urine), and left to ferment. When dry, it was crushed into powder and was ready to be used in a dye pot.
Woad was a very expensive trade good and the market became so large, farmers almost caused a famine from switching their grain fields into fields of woad. This led to the adoption of using Asian indigo and the creation of synthetic indigo. Woad dye can create many colors, ranging from pale light blue to vibrant cobalt. It is a natural alternative to the synthetic indigo (which contains formaldehyde).
This light-fast dye, used since before the 14th century, is still a fantastic option for natural dyeing. Used in conjunction with other dyes, one can create a multitude of colors for any project.